Answer:
option C
30m/s
Explanation:
preciesly 29.4
Answer:
The answer would be B. 30 m/s
Explanation:
Acceleration due to gravity is 9.8m/s per second.
So 9.8 × 3 = 29.4
closest to 29.4 is 30
An empty 12,954 kg railroad car, traveling at a speed of 28 m/s strikes a partially filled 17,616 kg railroad car moving in the same direction at a speed of 5 m/s. What is the total momentum of the two railroad cars AFTER the collision?
Answer:
450792 kgm/s
Explanation:
by conservation of momentum,
total momentum AFTER collision = total momentum BEFORE collision
=mv+m'v'
=12954×28+17616×5
=450792 kgm/s
A swimmer heading directly across a river that is 200 m wide reaches the opposite bank in 6 min 40 s. During this swim, she is swept downstream 480 m. How fast can she swim in still water
Answer:
The speed of the swimmer in stil water is 0.5 m/s
Explanation:
Given;
total time taken to swim across = 6 mins 40 s = (6 x 60s) + 40 s = 400 s
width of the river, = 200 m
Please find the image attached for explanation.
PLEASE ANSWR 1ST AND I WILL MARK U BRAINLIEST
Two statements are given- one labeled Assertion (A) and the other labeled Reason ®. Select
the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
a. Both A and R are true, and R is correct explanation of the assertion.
b. Both A and R are true, but R is not the correct explanation of the assertion.
c. A is true, but R is false.
d. A is false, but R is true.
Assertion: An object has a negative acceleration.
Reason: The velocity of an object decreases in the same direction.
Answer:
Where is the R statement?
you are given a set of facts regarding a lens : object heigh, and dostance to objects. Given this jnformation, how can you tell if you're dealing with a concave or convex lens
Answer:
concave curves inward like an hourglass and convex is an outward curve like a football
Explanation:
hope this helps
differentiate between step up and step down transformer
Answer:
The main difference between the step-up and step-down transformer is that the step-up transformer increases the output voltage, while the step-down transformer reduces the output voltage.
a. A horse pulls a cart along a flat road. Consider the following four forces that arise in this situation.
1. the force of the horse pulling on the cart
2. the force of the cart pulling on the horse
3. the force of the horse pushing on the road
4. the force of the road pushing on the horse
b. Suppose that the horse and cart have started from rest; and as time goes on, their speed increases in the same direction. Which one of the following conclusions is correct concerning the magnitudes of the forces mentioned above?
1. Force 1 exceeds Force 2.
2. Force 2 is less than Force 3.
3. Force 2 exceeds Force 4.
4. Force 3 exceeds Force 4.
5. Forces 1 and 2 cannot have equal magnitudes.
Answer:
a) F₁ = F₂, F₃ = F₄, b) the correct answer is 3
Explanation:
a) In this exercise we have several action and reaction forces, which are characterized by having the same magnitude, but different direction and being applied to different bodies
Forces 1 and 2 are action and reaction forces F₁ = F₂
Forces 3 and 4 are action and reaction forces F₃ = F₄
as it indicates that the
b) how the car increases if speed implies that force 1> force3
F₁ > F₃
therefore the correct answer is 3
Find the ratio of the diameter of copper to iron wire, if they have the same resistance per unit length (as they might in household wiring). dCu dFe =
Answer:
The ratio of diameter of copper wire to the iron wire is 0.42.
Explanation:
length of both the wires is same as L and resistance is R.
resistivity of copper = 1.7 x 10^-8 ohm m
resistivity of iron = 9.7 x 10^-8 ohm m
Let the diameter of copper is d and for iron is d'.
The formula of the resistance is
[tex]R = \rho\times\frac{L}{A}\\\\R = \rho\times\frac{4L}{\pi d^2}.... (1)\\And\\ R = \rho'\times\frac{4L}{\pi d'^2}.... (2)\\\\comparing (1) by (2)\\\\1.7\times10^{-8}\times\frac{4L}{\pi d^2}=9.7\times10^{-8}\times\frac{4L}{\pi d'^2}\\\\d : d' = 0.42[/tex]
Help!!
A table is pushed across the floor for a distance of 32 m with a force of 320 N in 150 seconds. How much power was used?
A.70.2W
B.68.3W
C.56.7W
D.49.8W
Compute the work done on the table:
W = Fd = (320 N) (32 m) = 10,240 J
Divide this by the given time duration to get the power output:
P = W/∆t = (10,240 J) / (150 s) ≈ 63.3 W
What is the friction force on a box that has a mass of 15kg as it slides across the floor. The coefficient of friction of the not very clean floor is 0.25
please explain everything including formula used
Answer:
36.75 N
Explanation:
Applying
F = mgμ................. Equation 1
Where F = Friction force on the box, m = mass of the box, g = acceleration due to gravity of the box, μ = coefficient of static friction
From the question,
Given: m = 15 kg, μ = 0.25
Constant: g = 9.8 m/s²
Substitute these values into equation 1
F = 15(9.8)(0.25)
F = 36.75 N
Hence the friction force on the box is 36.75 N
1. Convert the following length into meters
a. 123.50mm
b. 560cm
c. 100dm
d. 125.89km
A truck is hauling a 300-kg log out of a ditch using a winch attached to the back of the truck. Knowing the winch applies a constant force of 2850 N and the coefficient of kinetic friction between the ground and the log is 0.45, determine the time for the log to reach a speed of 0.5 m/s
Answer:
0.1 s
Explanation:
The net force on the log is F - f = ma where F = force due to winch = 2850 N, f = kinetic frictional force = μmg where μ = coefficient of kinetic friction between log and ground = 0.45, m = mass of log = 300 kg and g = acceleration due to gravity = 9.8 m/s² and a = acceleration of log
So F - f = ma
F - μmg = ma
F/m - μg = a
So, substituting the values of the variables into the equation, we have
a = F/m - μg
a = 2850 N/300 kg - 0.45 × 9.8 m/s²
a = 9.5 m/s² - 4.41 m/s²
a = 5.09 m/s²
Since acceleration, a = (v - u)/t where u = initial velocity of log = 0 m/s (since it was a rest before being pulled out of the ditch), v = final velocity of log = 0.5 m/s and t = time taken for the log to reach a speed of 0.5 m/s.
So, making t subject of the formula, we have
t = (v - u)/a
substituting the values of the variables into the equation, we have
t = (v - u)/a
t = (0.5 m/s - 0 m/s)/5.09 m/s²
t = 0.5 m/s ÷ 5.09 m/s²
t = 0.098 s
t ≅ 0.1 s
instrument used in measurement Amount of substance
Answer:
For liquids: A measuring cylinder is used.
For solid: Over flow can is used
Answer:
i think a measuring cylinder
A hoop rolls with constant velocity and without sliding along level ground. Its rotational kinetic energy is:______a- half its translational kinetic energyb- the same as its translational kinetic energyc- twice its translational kinetic energyd- four times its translational kinetic energy
Answer:
The same as its translational KE.
The easy way to do this is to make up numbers and use them.
So, I'll say m=2 and r=3. I will also say v=3 .
Rot. Inertia of a hoop is mr^2. So the rot KE is: 1/2 (mr^2)(w^2)
note: (1/2*I*w^2)
Translational kinetic energy is basically normal KE, so 1/2(m)(v^2)
Now, lets plug our made up values in:
Rot Ke : 1/2 (9*2)(3/3) *note w = v/r
Tran Ke: 1/2(2)(9)
Rot Ke: 9
Tran Ke: 9
9=9, same.
Two thin conducting plates, each 56.0 cm on a side, are situated parallel to one another and 7.0 mm apart. If 10^-10 electrons are moved from one plate to the other, what is the electric field between the plates?
Answer:
[tex]E=576.5V/m[/tex]
Explanation:
From the question we are told that:
Length [tex]l=56.0cm=0.56m[/tex]
Distance apart [tex]d=7.0mm=0.007m[/tex]
Electron Transferred [tex]n=10^{-10}[/tex]
Therefore
Total Charge
Since Charge on each electron is
[tex]e=1.602*10^{-19}[/tex]
Therefore
[tex]T=1.602*10^{-19} *10^{10}[/tex]
[tex]T=1.602*10^{-9}[/tex]
Generally the equation for Charge density is mathematically given by
[tex]\rho=T/A[/tex]
Where
Area
[tex]A=0.56*0.56[/tex]
[tex]A=0.3136[/tex]
Therefore
[tex]\rho=1.602*10^{-9}/0.3136[/tex]
[tex]\rho=5.10*10^{-9}[/tex]
Generally the equation for Electric Field in the capacitor is mathematically given by
[tex]E=\frac{\rho}{e_0}[/tex]
[tex]E=\frac{5.10*10^{-9}}{8.85x10{-12}}[/tex]
[tex]E=576.5V/m[/tex]
A ball is thrown horizontally at a speed of 24 meters per second from the top of a cliff. If the ball hits the ground 6.0 seconds later, approximately how high is the cliff?
Answer:
144 meters
Explanation:
it takes 6 seconds to hit the ground right and the ball lays off 24 m per second .
so by the time the ball hits the ground 6 seconds passed. so that means the cliff is 6.0×24=144
A 8.37*10^-5 F capacitor has 2.15*10^-4 C of charge on its plates. How much energy is stored on the capacitor
Answer:
2.76*10^-4
Explanation:
Trust me :)
Sunsets are a deep red because A) tiny particles in the air are more efficient at scattering short wavelength light than they are at scattering long wavelength light. Hence, long wavelength light ends up coming directly towards you. B) most polluting gases and dust particles in the air are reddish in color and lend their color to that of the sky. C) air molecules absorb red light more efficiently than they do blue light because of their electron orbitals. D) air molecules absorb blue light more efficiently than they do red light because of their electron orbitals.
Answer:
i think its A
Answer:tiny particles in the air are more efficient at scattering short wavelength light than they are at scattering long
Explanation:
What is energy?
Select one:
A force that must be exerted in order to accelerate an object.
A property that must be transferred to perform work.
A particle that can be absorbed to change momentum.
A system that can be rearranged in order to change its state.
Answer:
Energy is:
A property that must be transferred to perform work.
Answer:
EnergyExplanation:
A property that must be transferred to perform work .Hope it is helpful to you Stay safe healthy and happy ☺️explain why this is important for life on earth
Answer:
THIS is very important.
Explanation:
If the word "this" was never invented, people wouldn't have a way to tell another person what is directly in front of them.
BTW this is a joke.
The image shows the right-hand rule being used for a current-carrying wire.
An illustration with a right hand with fingers curled and thumb pointed up.
Which statement describes what the hand shows?
When the current flows down the wire, the magnetic field flows out on the left side of the wire and in on the right side of the wire.
When the current flows up the wire, the magnetic field flows out on the left side of the wire and in on the right side of the wire.
When the current flows down the wire, the magnetic field flows in on the left side of the wire and out on the right side of the wire.
When the current flows up the wire, the magnetic field flows in on the left side of the wire and out on the right side of the wire.
Answer:
The answer is (D): When the current flows up the wire, the magnetic field flows in on the left side of the wire and out on the right side of the wire.
Explanation:
Which of the following elements has the largest atomic radius?
Silicon
Aluminum
Sulfur
Phosphorous
Answer:
francium
Atomic radii vary in a predictable way across the periodic table. As can be seen in the figures below, the atomic radius increases from top to bottom in a group, and decreases from left to right across a period. Thus, helium is the smallest element, and francium is the largest.
if p=2i+4j+3k and q=I+5j-2k,find P×q.
Answer:
[tex]p\times q=-23i+7j+6k[/tex]
Explanation:
We are given that
p=2i+4j+3k
q=i+5j-2k
We have to find pxq
We know that
[tex]p\times q=\begin{vmatrix} i&j &k\\ 2&4 & 3\\ 1& 5 & -2\end{vmatrix}[/tex]
[tex]p\times q=i(-8-15)-j(-4-3)+k(10-4)[/tex]
[tex]p\times q=-23i+7j+6k[/tex]
Hence,[tex]p\times q=-23i+7j+6k[/tex]
A boy throws a ball straight up with a speed of 21.5 m/s. The ball has a mass of 0.19 kg. How much gravitational potential energy will the ball have at the top of its flight? (Assume there is no air resistance.) A. 43.9 J B. 37.5 J C. 48.5 J D. 41.2 J
Answer:
Explanation:
The equation fo potential energy is PE = mgh, where m is the mass of the ball, g is the pull of gravity (constant at 9.8), and h is the max height of the ball. What we do not have here is that height. We need to first solve for it using one-dimensional equations. What we have to know above all else, is that the final velocity of an object at its max height is always 0. That allows us to use the equation
[tex]v_f=v_0+at[/tex] where vf is the final velocity and v0 is the initial velocity. We will find out how long it takes for the object to reach that max height first and then use that time to find out what that max height is. Baby steps here...
0 = 21.5 + (-9.8)t and
-21.5 = -9.8t so
t = 2.19 seconds (Keep in mind that if I used the rules correctly for sig fig's, the answer you SHOULD get is not one shown, so I had to adjust the sig fig's and break the rules. But you know what they say about rules...)
Now we will use that time to find out the max height of the object in the equation
Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in:
Δx = [tex]21.5(2.19)+\frac{1}{2}(-9.8)(2.19)^2[/tex] which simplifies down a bit to
Δx = 47.1 - 23.5 so
Δx = 23.6 meters.
Now we can plug that in to the PE equation to find the PE of the object:
PE = (.19)(9.8)(23.6) so
PE = 43.9 J
A constant force moves an object along the line segment from to . Find the work done if the distance is measured in meters and the force in newtons.
This question is incomplete, the complete question is;
Flag
A constant force F = 6i+8j-6k moves an object along a straight line from point (6, 0, -10) to point (-6, 7, 2).
Find the work done if the distance is measured in meters and the magnitude of the force is measured in newtons.
Answer:
the work done is -88 J
Explanation:
Given the data in the question;
we know that;
Work done = F × S
where constant force F = ( 6i + 8j - 6k )
S = ( -6i + 7j + 2k ) - ( 6i + 0j - 10k )
S = ( (-6i - 6i) + (7j - 0j) + ( 2k - ( -10k) ) )
S = ( -12I + 7j + 12k )
so
Work force = ( 6i + 8j - 6k ) × ( -12I + 7j + 12k )
Work force = ( 6 × -12 ) + ( 8 × 7 ) + ( -6 × 12 )
Work force = -72 + 56 - 72
Work force = -88 J
Therefore, the work done is -88 J
A spring scale hung from the ceiling stretches by 6.1cm when a 2.0kg mass is hung from it. The 2.0kg mass is removed and replaced with a 2.8kg mass.What is the stretch of the spring?
Using only astronomical data from the Appendix E in the textbook, calculate the speed of the planet Venus in its essentially circular orbit around the sun.
Venus = 4.87x10^24
Answer:
[tex]v=3.49\times 10^4\ m/s[/tex]
Explanation:
Given that,
Mass of Venus, [tex]M_V=4.87\times 10^{24}\ kg[/tex]
We know that,
Mass of Sun, [tex]M_s=1.98\times 10^{30}\ kg[/tex]
The distance between the center of Sun and the center of Venus is [tex]1.08\times 10^{11}\ m[/tex]
We need to find the peed of the planet Venus in its essentially circular orbit around the sun. using the formula,
[tex]v=\sqrt{\dfrac{GM_s}{r}}[/tex]
Put all the values,
[tex]v=\sqrt{\dfrac{6.67\times 10^{-11}\times 1.98\times 10^{30}}{1.08\times 10^{11}}}\\\\v=3.49\times 10^4\ m/s[/tex]
So, the speed of the planet venus is [tex]3.49\times 10^4\ m/s[/tex].
The cycle is a process that returns to its beginning, but it does not repeat
itself.
True
False
What are the messing forces that would make the object be in equilibrium?
Answer:
A) 20 N, B) 20 N, & C) 8 N
Explanation:
For the object to be in equilibrium, the upward forces must be equal to the downward forces and the forward forces must be equal to the backward forces.
1. Determination of A and B.
Forward forces = Backward forces
A + 10 + B = 25 + 25
A + 10 + B = 50
Collect like terms
A + B = 50 – 10
A + B = 40
Assume A and B to be equal. Thus, A is 20 N and B is 20 N.
2. Determination of C
Upward forces = Downward forces
C + 112 = 20 + 100
C + 112 = 120
Collect like terms
C = 120 – 112
C = 8 N
Thus, for the object to be in equilibrium, A must be 20 N, B must be 20 N and C must be 8N.
A block of mass m is moved over a distance d. An applied force F is directed perpendicularly to the block’s displacement. How much work is done on the block by the force F?
zero
Explanation:
Work W is defined as
W = F•d = Fdcos(theta)
and it is a dot product of the force and displacement and theta is angle between F and d Since the force is perpendicular to d, angle is 90° thus cos90 = 0. Hence work is zero.
An electric field is given by in units of N/C when is in meters. What is the potential difference from point B at (0,7) m to point A at (7,0) m
Complete Question
An electric field is given by E= (5x, 0, 0) in units of N/C when x is in meters. What is the potential difference VA - VB from point B at (0,7) m to point A at (7,0) m? V
Answer:
[tex]V_A-V_B=-122.5V[/tex]
Explanation:
From the question we are told that:
Position of point [tex]B=(0,7) m[/tex]
Position of point [tex]A=(7,0) m[/tex]
Generally the equation for pd across the points is mathematically given by
[tex]V_A-V_B=-\int_0^7(5x)d[/tex]
[tex]V_A-V_B=-[\frac{5x^2}{2}]_0^7[/tex]
[tex]V_A-V_B=-[\frac{5(7)^2}{2}][/tex]
[tex]V_A-V_B=-122.5V[/tex]
