Answer:
a) The force that the worker must apply has a magnitude of 75.317 newtons.
b) The external force does a work of 0.301 joules.
c) The friction force does a work of -0.301 joules.
d) Both normal force and gravity have done a work of 0 joules.
e) The total work done on the crate is 0 joules.
Explanation:
a) As the crate is moving at constant velocity, we know that magnitude of the force done on the crate must be equal to the friction force. Hence, we must use the following formula:
[tex]F = \mu\cdot m\cdot g[/tex] (1)
Where:
[tex]F[/tex] - External force, in newtons.
[tex]\mu[/tex] - Coefficient of kinetic friction, no unit.
[tex]m[/tex] - Mass, in kilograms.
[tex]g[/tex] - Gravity acceleration, in meters per square second.
If we know that [tex]\mu = 0.24[/tex], [tex]m= 32\,kg[/tex] and [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], then the external force is:
[tex]F = (0.24)\cdot (32\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)[/tex]
[tex]F = 75.317\,N[/tex]
The force that the worker must apply has a magnitude of 75.317 newtons.
b) The direction of the force is parallel to the direction of motion. The work done by this force ([tex]W_{F}[/tex]), in joules, is determined by this formula:
[tex]W_{F} = F\cdot \Delta s[/tex] (2)
Where [tex]\Delta s[/tex] is the distance travelled by the crate, in meters.
If we know that [tex]F = 75.317\,N[/tex] and [tex]\Delta s = 0.004\,m[/tex], then the work done by the force is:
[tex]W_{F} = (75.317\,N)\cdot (0.004\,m)[/tex]
[tex]W_{F} = 0.301\,J[/tex]
The external force does a work of 0.301 joules.
c) The direction of the friction force is antiparallel to the direction of motion. The work done by this force ([tex]W_{f}[/tex]), in joules, is determined by this formula:
[tex]W_{f} = -W_{F}[/tex] (3)
[tex]W_{f} = -0.301\,J[/tex]
The friction force does a work of -0.301 joules.
d) The direction of the normal force is perpendicular to the direction of motion. Therefore, no work is done due to normal force.
[tex]W_{N} = 0\,J[/tex]
Likewise, no work is done by gravity.
[tex]W_{g} = 0\,J[/tex]
Both normal force and gravity have done a work of 0 joules.
e) The total work is the sum of the works done by the external force and the friction force:
[tex]W = W_{F}+W_{f}[/tex]
[tex]W = 0.301\,J - 0.301\,J[/tex]
[tex]W = 0\,J[/tex]
The total work done on the crate is 0 joules.
If you are driving a car with a velocity of -25 m/s and you have an acceleration of -2 m/s^2, are you speeding up or slowing down? Why?
Answer:
Hmmm...
This is a bit tricky
Ok...
Negative Velocity means you're Moving in the Opposite direction....
Negative Acceleration (deceleration) means you're slowing down.
Deceleration would mean slowing down if you were Moving with a Positive velocity.
But In this case...
You're Moving with negative velocity and Negative acceleration...
This simply means that the acceleration and velocity vector are in the same direction....
Its means that...
"YOU'RE SPEEDING UP"
Just that you're doing it in the opposite direction.
Hope this helps.
A rock is pulled back in a slingshot as shown in the diagram below. The elastic on the slingshot is displaced 0.2 meters from its initial position. The rock is pulled back with a force of 10 newtons.
When the rock is released, what is its kinetic energy?
Answer:
id
Explanation:
i don't know
The rock takes 8.16s to return to its release point. Given that the elastic band provides a speed of 40m/s to the rock in 10 cm stretch.
What will be the speed of the rock?Initial speed of the rock, u = 40m/s
Final position of the rock s = 0m taking the release point as reference. The rock takes 8.16s to return to its release point. Given that the elastic band provides a speed of 40m/s to the rock in 10 cm stretch.
Nuclear energy is a useful source of power but has disadvantages. The disadvantage of nuclear energy is it produces dangerous waste.
Initial speed of the rock, u = 40m/s
Final position of the rock s = 0m taking the release point as reference
From the second equation of motion:
solving above we get:
t = 0s or t = 8.16s, t =0 seconds is neglected since it represents the initial position which is the same as the final position at t = 8.16s
So, the rock takes 8.16 seconds to return to the release point.
Therefore, The rock takes 8.16s to return to its release point. Given that the elastic band provides a speed of 40m/s to the rock in 10 cm stretch.
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I feel bad for people who don't know about this site and suffer with thier homework's
same bruuh i could say it any better
Answer:
right? omg i would be failing if it weren't for people helping w my home work haha
Give the missing ammeter reading a and b. suggest why more current flow through some bulbs than through others Grade 10 question and Answer
Answer:
becaude of electricity
Please solve this problem!
Answer:
Send a clear photo again
Explanation:
And tag me
what is the formula to calculate the speed
Answer:
speed=to distance ÷time , thank me later
The position of a particle changes linearly with time, i.e. as one power of t, as given by the following: h(t) = ( 4.1 t + 5.5 ) meters. Find the speed of the particle, in meters per second.
Answer:
v = 4.1 m / s
Explanation:
Velocity is defined by the relation
v =[tex]\frac{dx}{dt}[/tex]
we perform the derivative
v = 4.1 m / s
Another way to find this magnitude is to see that the velocity on the slope of a graph of h vs t
v = [tex]\frac{\Delta x}{\Delta t}[/tex]
Δx = v Δdt + x₀
h= 4.1 t + 5.5
v = 4.1 m / s
x₀ = 5.5 m
The heat capacity of sodium metal is 1500 JK-1, if the mass of the sodium metal is 75 kg, the specific
heat capacity would be
Explanation:
the answer is in the image above
What must be the same for two resistors that are connected in parallel?
Answer:
the voltage will be the same across all resistors
Explanation:
the total voltage supplied to the circuit will remain the same across all resistors
Andrea, a 59.0 kg sprinter, starts a race with an acceleration of 3.900 m/s2. If she accelerates at that rate for 12.00 m and then maintains that velocity for the remainder of a 100.00 m dash, what will her time (in s) be for the race
Answer:
her total time taken for the race is 11.58 s
Explanation:
mass of the sprinter, m = 59 kg
acceleration of the sprinter, a = 3.9 m/s²
initial distance covered by the sprinter, d₁ = 12 m
Time taken to cover the first 12 m;
d₁ = ut + ¹/₂at²
where;
u is her initial velocity = 0
d₁ = ¹/₂at²
2d₁ = at²
[tex]t_1 = \sqrt{\frac{2d_1}{a} } \\\\t_1 = \sqrt{\frac{2\times 12}{3.9} }\\\\t_1 = 2.48 \ s[/tex]
The velocity of the sprinter at the end of the 12 m;
v = u + at
v = 0 + at
v = at
v = 3.9 x 2.48
v = 9.67 m/s
The last distance covered by the sprinter at the constant velocity of 9.67 m/s = (100 - 12)m = 88 m
The time taken to cover 88 m with an initial velocity of 9.67 m/s is calculated as;
d₂ = vt + ¹/₂at²
Since the velocity is constant, the acceleration, a = 0
d₂ = vt₂
t₂ = d₂/v
t₂ = 88 / 9.67
t₂ = 9.1 s
The total time taken for the race = t₁ + t₂
= 2.48 s + 9.1 s
= 11.58 s
1. Why does the shape of the lens in your eye change?
To alter the amount of light that enters the eye
to focus the light
to alter the image sent to the brain
Answer:
to focus the link light
Explanation:
Because the lens is flexible and elastic, it can change its curved shape to focus on objects and people that are either nearby or at a distance. ... The ciliary muscles, which are part of the ciliary body, are attached to the lens and contract or release to change the lens shape and curvature.
Answer:
to focus the link light
Explanation:
vote brainliest I never got voted brainliest plssss
Which circuits are parallel circuits?
0
WA
AHE
Answer:
the 5 is because u have to select the currents and volts which gives us 2 and 1 plus 3 is 6 but if we rest 1 is 5, thats the answer
С какой скоростью велосипедист проходит закругление велотрека радиусом 25 м, если центростремительное ускорение при этом 4 м/с2?
10
20
400
100
Explanation:
to determine light brightness
to determine planet compositition
to determine the ages of p
what are the 6 essential nutrients
Answer:
There are six major nutrients: Carbohydrates (CHO), Lipids (fats), Proteins, Vitamins, Minerals, Water.
Explanation:
9. What part of the eye contains muscles that regulate the amount of light that is allowed to enter the eye?
Answer: the iris
Explanation: I looked it up
Answer:
Iris
Explanation:
Because (iris) has muscles that can expand/contract depends to the amount of light that pupil needs to process/figure out images.
how can u tell matched forces act on objects?
Answer:If an object's speed changes, or if it changes the direction it's moving in,
then there must be forces acting on it. There is no other way for any of
these things to happen.
Once in a while, there may be a group of forces (two or more) acting on
an object, and the group of forces may turn out to be "balanced". When
that happens, the object's speed will remain constant, and ... if the speed
is not zero ... it will continue moving in a straight line. In that case, it's not
possible to tell by looking at it whether there are any forces acting on it
The number of radioactive nuclides from a radioactive source has reduced to 1/6
from its original value in 60 seconds. Find the decay constant for this source.
Answer:
λ = 0.03 s⁻¹
Explanation:
The formula for decay constant can be used as follows:
[tex]N = N_oe^{-\lambda t}\\\\\frac{N}{N_o} = e^{-\lambda t}[/tex]
where,
[tex]\frac{N}{N_o}[/tex] = ratio of remaining nuclei to the initial value of nuclei = [tex]\frac{1}{6}[/tex] = 0.167
t = time = 60 s
λ = decay constant = ?
Therefore,
[tex]0.167 = e^{-\lambda(60\ s)}\\\\-\lambda (60\ s) = ln(0.167)\\\\\lambda = \frac{-1.7917}{- 60\ s}[/tex]
λ = 0.03 s⁻¹
An investigator collects a sample of a radioactive isotope with an activity of 490,000 Bq.48 hours later, the activity is 110,000 Bq. Part A For the steps and strategies involved in solving a similar problem, you may view a Video Tutor Solution What is the half-life of the sample?
Answer:
The correct answer is "22.27 hours".
Explanation:
Given that:
Radioactive isotope activity,
= 490,000 Bq
Activity,
= 110,000 Bq
Time,
= 48 hours
As we know,
⇒ [tex]A = A_0 e^{- \lambda t}[/tex]
or,
⇒ [tex]\frac{A}{A_0}=e^{-\lambda t}[/tex]
By taking "ln", we get
⇒ [tex]ln \frac{A}{A_0}=- \lambda t[/tex]
By substituting the values, we get
⇒ [tex]-ln \frac{110000}{490000} = -48 \lambda[/tex]
⇒ [tex]-1.4939=-48 \lambda[/tex]
[tex]\lambda = 0.031122[/tex]
As,
⇒ [tex]\lambda = \frac{ln_2}{\frac{T}{2} }[/tex]
then,
⇒ [tex]\frac{ln_2}{T_ \frac{1}{2} } =0.031122[/tex]
⇒ [tex]T_\frac{1}{2}=\frac{ln_2}{0.031122}[/tex]
[tex]=22.27 \ hours[/tex]
A stone was dropped off a cliff and hit the ground with a speed of 136 ft/s. What is the height of the cliff
Answer:
Explanation:
Use the equation
[tex]v^2=v_0^2+2a[/tex]Δx
In this dimension (the y dimension...the only one we have to care about for this problem), here's what we know:
a = -32 ft/s/s
v₀ = 0 m/s (since someone was holding the stone still before it was dropped)
v = 136 ft/s
Δx = ??
Filling in:
[tex]136^2=0^2+2(-32)[/tex]Δx so
Δx = [tex]\frac{136^2}{2(-32)}[/tex] so
Δx = -289 feet (negative because the stone dropped that many feet below the point from which it was dropped, but you would answer a height question with the positive of this number. If you were asked how far the stone dropped, it would be negative; if you're asked how tall the cliff is, that would be positive)
can some one tell the answers
A uniform copper wire has a resistance of 100 ohms. If the wire is cut into 10 equal lengths, what will be the resistance of each piece
Answer:
Since resistance is proportional to length R = K L / A
the resistance of each piece would be R / 10 = 10 ohms
A copper wire is the conductor wire. If the wire is cut into 10 equal lengths, the resistance of each piece will be 10 ohms.
What is resistance?Resistance is the opposition to the flow of electrons in the conductor wire.
Given is the total resistance of the wire is 100 ohms.
Resistance is directly proportional to the length of the wire. When the wire is cut into 10 pieces, the new resistance will be
[tex]\dfrac{R}{10} =\dfrac{100}{10} =10 \:\rm ohms[/tex]
Hence, the resistance of each piece will be 10 ohms.
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What happens when electron loses all its energy in x ray..
Answer:
An excited atom is unstable and tends to rearrange itself to return to its lowest energy state. ... The lines in an emission spectrum occur when the electron loses energy, "falls back", from a higher energy state to a lower one emitting photons at different frequencies for different energy transitions.
Explanation:
12. What type of lens is pictures below?
Oconverging lens
diverging lens
This is convex lens .
hence It's a converging lens .
The picture shown is a type of converging lens. The correct option is A.
What is a converging lens?A converging lens, also known as a convex lens, is a type of optical lens that is thicker in the middle than at the edges. It is shaped like a curved-outward disc and is commonly used in optical systems such as cameras, telescopes, and microscopes. When light passes through a converging lens, it bends inward and converges at a focal point located on the other side of the lens.
This focal point is determined by the curvature of the lens and its refractive index, which affects how much the light is bent. The distance between the lens and the focal point is called the focal length, and it determines the magnification and the image size produced by the lens. Converging lenses are used in many applications that require focusing and magnifying light, such as correcting vision problems and creating images in photography and microscopy.
Therefore, The correct answer is converging lens.
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If you borrow $12250 and pay $147 in annual interest, the APR on your loan is 1.2% 14.7% 1.23% 7.35%
Answer: 1.2%
Explanation:
Given
If one borrows $12,250
and give $147 interest on it
Then the interest is given from the formula
[tex]\Rightarrow S.I=\dfrac{P\times R\times T}{100}\\\\\Rightarrow 147=\dfrac{12,250\times R\times 1}{100}\\\\\Rightarrow R=\dfrac{147}{122.50}\\\\\Rightarrow R=1.2\%[/tex]
Thus, the annual rate of interest is 1.2%
What is the resistance of a 3.5 m copper wire (Rho= 1.7x10-8 Ohm·m) that 1 point
has a cross-sectional area of 5.26x10-6 m2? Use the equation below. *
R=
pl
А
4.1 x 10-3 ohms
1.1 x 10 3 ohms
9.2 x 10-4 ohms
1.1x 10-2 ohms
Answer:
(D)
Explanation:
Given :
l=3.5 m
[tex]A=5.26*10^{-6}[/tex] [tex]m^{2}[/tex]
[tex]p=1.7*10^{-8} ohm.m[/tex]
Resistance can be calculated as :
[tex]R=p\frac{l}{A} \\R=1.7*10^{-8} \frac{3.5}{5.26*10^{-6} }[/tex]
[tex]R=\frac{5.95*10^{-2} }{5.26} \\R=1.13*10^{-2}[/tex]
Resistance of the wire will be 1.1×[tex]10^{-2}[/tex] ohms
Option D is correct
Which one will it be
Answer: D
The force decreases inversely proportional to 1/r(squared)
Explanation:
I looked it up im sure this is correct
Answer:
option d
Explanation:
Two objects are attracted to each other by a gravitational force F. ... As the distance r from the center of the planet increases, what happens to the force of gravity on the rocket? The force decreases inversely proportional to 1/r(squared) A spacecraft is orbiting Earth with an orbital radius r.
the force of gravity is represented as
F = GM1M2/r²
now the mass of warth and rocket is considered to be constant and G is a universal constant so it can be said
F is inverse to r²
therefore as the value of r increases that is distance between earth and rocket increases the force decreases
(Follows inverse square law)
A motorcycle, which has an initial linear speed of 5.0 m/s, decelerates to a speed of 3.5 m/s in 4.5 s. Each wheel has a radius of 0.60 m and is rotating in a counterclockwise (positive) directions. What is (a) the constant angular acceleration (in rad/s2) and (b) the angular displacement (in rad) of each wheel?
Explanation:
Given that,
A motorcycle, which has an initial linear speed of 5.0 m/s, decelerates to a speed of 3.5 m/s in 4.5 s. Each wheel has a radius of 0.60 m and is rotating in a counterclockwise (positive) directions.
Angular acceleration, [tex]\alpha =\dfrac{\omega_2-\omega_1}{t}[/tex]
[tex]\alpha =\dfrac{\dfrac{v_2}{r}-\dfrac{v_1}{r}}{t}[/tex]
Put all the values,
[tex]\alpha =\dfrac{\dfrac{3.5}{0.6}-\dfrac{5}{0.6}}{4.5}\\\\=-0.56\ rad/s^2[/tex]
Angular displacement,
[tex]\theta=\dfrac{\omega_2^2-\omega_1^2}{2\alpha}\\\\\theta=\dfrac{(\dfrac{v_2}{r})^2-(\dfrac{v_1}{r})^2}{2\alpha}\\\\\theta=\dfrac{(\dfrac{3.5}{0.6})^2-(\dfrac{5}{0.6})^2}{2\times (-0.56)}\\\\=31.62\ rad[/tex]
Hence
Answer:
(a) The angular acceleration is - 0.56 rad/s^2.
(b) The angular displacement is 31.6 rad.
Explanation:
initial velocity, u = 5 m/s
final velocity, v = 3.5 m/s
radius, r = 0.6 m
time, t = 4.5 s
initial angular velocity, wo = u/r = 5/0.6 = 8.33 rad/s
final angular velocity, w = v/r = 3.5 / 0.6 = 5.83 rad/s
(a) Use the first equation of motion to fine the angular acceleration.
[tex]w = w_o + \alpha t \\\\5.83 = 8.33 + \alpha \times 4.5\\\\\alpha = - 0.56 rad/s^2[/tex]
(b) Use third equation of motion to find the angular displacement
[tex]w^2 = w_0^2 + 2\alpha \theta \\\\5.83^2 =8.833^2 - 2 \times 0.56\times \theta \\\\\theta =31.6 rad[/tex]
which of the following is a correct statement. a. In dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are constant and the voltage across the inductances are constant. b. In dc steady state conditions, the voltages across the capacitors are zero and the currents through the capacitance are constant. The current through the inductors are constant and the voltage across the inductances are zero. c. In dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are zero and the voltage across the inductances are constant. d. WIn dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are constant and the voltage across the inductances are zero.
Answer:
d. In dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are constant and the voltage across the inductances are zero.
Explanation:
The current through a capacitor is given by i = CdV/dt where C = capacitance of capacitor and V = voltage across capacitor. At steady state dV/dt = 0 and V = constant. So, i = CdV/dt = C × 0 = 0.
So, in dc steady state, the voltage across a capacitor is constant and the current zero.
The voltage across an inductor is given by V = Ldi/dt where L = inductance of inductor and i = current through inductor. At steady state di/dt = 0 and V = constant. So, V = Ldi/dt = L × 0 = 0.
So, in dc steady state, the voltage across an inductor is zero and the current constant.
So, In dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are constant and the voltage across the inductances are zero.
The answer is d.
Consider a simple pendulum that consists of a massless 2.00-meter length of rope attached to a 5.00-kg mass at one end. What is the period of oscillation for this simple pendulum
Answer:
2.8 seconds
Explanation: Given that a simple pendulum that consists of a massless 2.00-meter length of rope attached to a 5.00-kg mass at one end. What is the period of oscillation for this simple pendulum
The parameters given are :
Length = 2 m
Mass = 5kg
Using the formula below
T = 2 pi × sqrt ( L / g )
Substitute all the parameters into the formula.
T = 2 × 3.143 × sqrt ( 2 / 9.8 )
T = 2 × 3.143 × 0.4517
T = 2.838 s
Therefore, the period of oscillation for this simple pendulum is 2.8 s approximately.
2.
A rock, mass 4 kg, and a 1 kg stone fall freely from rest from a height of
100 m. After they fall for 2 seconds, the ratio of the rock's speed to the
stone's speed is
Answer:
44.72m/s
Explanation:
use th formula:vf²=vi²at
and then substitute the values
remember the units
If there is no air resistance, the speed of the free falling object from the same height will be the same. Therefore, the ratio of speed of the stone to that of rock for 2 seconds falling will be 1 : 1.
What is free falling ?An object freely falling under the force of gravitation is called the free falling body. Here, the acceleration of the object is the acceleration due to gravity.
For a freely falling body, the velocity v = g t
where g is the acceleration due to gravity and for earth g is 9.8 m/s².
Everybody falls with the same rate freely under the acceleration due to gravity if there is no air resistance at all.
Here, the time t = 2 s
then v = 9.8 m/s² × 2 s = 19.6 m/s.
the speed of both the rock and stone will be 19.6 m/s in the absence of air resistance. Hence, the ratio of their speed is 1 : 1.
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