Answer:
They are called beneficial mutations. They lead to new versions of proteins that help organisms adapt to changes in their environment. Beneficial mutations are essential for evolution to occur. They increase an organism's chances of surviving or reproducing, so they are likely to become more common over time.49. A block is pushed across a horizontal surface with a
coefficient of kinetic friction of 0.15 by applying a
150 N horizontal force.
(a) The block accelerates at the rate of 2.53 m/s2
Find the mass of the block.
(b) The block slides across a new surface while
experiencing the same applied force as before.
The block now moves with a constant speed.
What is the coefficient of kinetic friction between
the block and the new surface?
Answer:
(a) 37.5 kg
(b) 4
Explanation:
Force, F = 150 N
kinetic friction coefficient = 0.15
(a) acceleration, a = 2.53 m/s^2
According to the newton's second law
Net force = mass x acceleration
F - friction force = m a
150 - 0.15 x m g = m a
150 = m (2.53 + 0.15 x 9.8)
m = 37.5 kg
(b) As the block moves with the constant speed so the applied force becomes the friction force.
[tex]F = \mu m g \\\\150 = \mu\times 37.5\\\\\mu = 4[/tex]
A policeman kicks in a door with a force of 4500 N. What force does the door apply to the policeman’s leg?
Answer:
-4500 N
Source: Brainly
The police officer must be angry 0_0
Please help me with this...
And write all steps..
Answer:
[tex]2\frac{m}{s^2} =a[/tex]Explanation:
Use the kinematic equation.
[tex]v_{2} =v_{1} +at[/tex]This equation can be derived from [tex]f=ma[/tex], but we can just memorize, or look them up when needed as it saves us time.
Now we can plug our measurements into each variable to solve for acceleration.
[tex]18\frac{m}{s} =8\frac{m}{s} +a*5s[/tex]Subtract 8m/s from both sides.
[tex]10\frac{m}{s} =a*5s[/tex]Divide by 5 seconds. Left with acceleration in terms of [tex]\frac{m}{s^2}[/tex]
[tex]2\frac{m}{s^2} =a[/tex]when is the mass of an object if it exerts a force of 160 N and an acceleration of 8.15m/s^2
Answer:
f=ma.......m=f/a......m=20kg
the power in an electrical circuit is given by the equation p=/2 R, where /is the current flowing through the circuit and R is the resistance of the circuit. what is the power in a circuit that has a current of 12
A. 120 watts
B. 8.3 watts
C.144 watts
D. 14,400 watts
Complete Question:
What is the power in a circuit that has a current of 12 amps and a resistance of 100 ohms?
Answer:
D. 14,400 watts
Explanation:
The electrical power of an electric circuit can be defined as a measure of the rate at which energy is either produced or absorbed in the circuit.
Mathematically, electrical power is given by the formula;
[tex] Electrical \; power = current * voltage [/tex]
This ultimately implies that, the quantity (current times voltage ) is electrical power and it is measured (S.I units) in Watt (W).
Given the following data;
Current = 12 AmperesResistance = 100 OhmsTo find the power in the circuit, we would use the following formula;
Power = I²R
Where;
I is current measured in Amperes.R is resistance measured in Ohms.Power = 12² * 100
Power = 144 * 100
Power = 144,000 Watts
Please help me with the following question:
Calculate the weight of a 68.0 kg person:
a) on the surface of the earth
b) at the top of Everest (8848 m above sea level).
c) has 2 1/2 times the radius of the earth
Thank you in advance :)
Answer: a. 667N
b. 665N
c. 54.5N
Explanation:
a) on the surface of the earth
W = mg
W = 68 × 9.81
= 667N
b) at the top of Everest (8848 m above sea level).
W =mg × R²/(R + H)²
W = 667 × [6378²/(6378 + 8.848)²
W = 665N
c) has 2 1/2 times the radius of the earth
W = mg × R²/(R + H)²
W = 667 × R²/(R + 2.5R)²
W = 54.5N
When an object is in a gravitational field, it has energy in its __________ __________ energy store.
Answer:
Gravitational potential
Explanation:
Any object that is not on the surface of the Earth, but at a height instead has potential energy. Eventually, this can become kinetic energy once the object falls.
When an object is in a gravitational field, it has energy in its gravitational potential energy store.
Question 4(Multiple Choice Worth 3 points)
(03.02 MC)
Which statement best reflects a change in weather?
Today is cloudy, but tomorrow will be clear and sunny.
The average rainfall has decreased over the past five years.
Ocean temperatures are projected to increase over time.
Glaciers are melting more rapidly now than in the past 100 years.
plzzz helpppp asap
Answer:
a is your answer.............
An elevator does 9.75 x 10(4) J of work on a person riding up to another floor. How much energy does the person gain
Answer:
9.75 x 10^4 J
Explanation:
Work done, W = 9.75 x 10^4 J
According to the work energy theorem, the change in kinetic energy is equal to the work done by all the forces.
So, here work done is 9.75 x 10^4 J so the change in kinetic energy is 9.75 x 10^4 J.
A solution has a pH of 8. Which best describes the solution?
a strong acid
a strong base
a weak acid
a weak base
Answer:
D
Explanation:
a weak base is the answer
Answer:
weak base because its near to 7 (neutral) and above 7 is base
¿Cuánto se demora el sonido en recorrer 3 metros de un cable de cobre, si su rapidez en él es de 3810 m/s
Answer:
1270 segundos
Explanation:
Dada,
Velocidad ( v ) = 3810 m/s
Distancia ( s ) = 3 m
Encontrar : -
Tiempo que tarda el sonido en viajar ( t ) = ?
Fórmula : -
s = d / t
t = d / s
= 3810 / 3
t = 1270 segundos
The gravitational force acting on various masses is measured on different planets. Measured values for the forces acting on the corresponding masses are shown in the data table. Analyze the data and develop a method for comparing the gravitational field strengths on the different planets. Use your method to compare the gravitational field strengths, and report your conclusions.
who is a meteorologist
Answer:
A meteorologist is a scientist that studies and examines Earth's atmosphere and its interactions with Earth's oceans, land, and biosphere.
Explanation:
Meteorologists use math and science to understand and predict changes in weather and climate.
PLEASE HELP!!!
Write the sentences in your copybook and draw a line through one of the words in
bold to complete each of these sentences about alkali metals correctly.
Alkali metals generally become more / less dense going down the group.
The melting and boiling points of alkali metals increase / decrease down the group.
The softness of alkali metals increases / decreases going down the group.
The speed with which alkali metals react with oxygen increases / decreases going
down the group.
Answer:
Densities increase down the group
MP and BP decrease down the group
Softness increased going down the group
Speed of reacting increases going down the group
what are scalors? give examples
Answer:
Scalars are quantities with only magnitude, as apposed to vectors, which have magnitude and direction
Scalars include, Distance, speed, mass, temperature, time, etc.
There is only a numerical value associated with these quantities
Vectors include, Displacement, velocity, force, acceleration, etc.
There will be both a numerical value, and a direction associated with these quantities
The boiling point of water is 1000 C at sea level. The boiling point of butane is -1.50C… If we leave liquid butane in a bowl on a table in a room where the temperature is 240C, butane will
A. evaporate.
B. condense.
C. freeze.
D. melt.
Answer: If we leave liquid butane in a bowl on a table in a room where the temperature is [tex]24^{o}C[/tex], butane will evaporate.
Explanation:
A temperature at which the the liquid and gaseous phase of a substance of a substance are present in equilibrium with each other is called boiling point.
For example, the boiling point of butane is -1.5 degree Celsius.
This means that at a temperature above -1.5 degree Celsius, butane will exist is gaseous state. That is, at a temperature of 24 degree Celsius butane will evaporate.
Thus, we can conclude that if we leave liquid butane in a bowl on a table in a room where the temperature is [tex]24^{o}C[/tex], butane will evaporate.
How can resonance overcome damping of an oscillating system?
Answer:
When one system vibrating at its natural frequency is put closer to a stationary system, the stationary system receives impulses.
At resonant frequency, the system vibrating at its own natural frequency suddenly goes on decreasing in order to cope with neighboring system.
These decrease in frequency is known as damping.
To catch a fast-moving ball, you extend your hand forward before contact with the ball and let it ride backward in the direction of the ball's motion. Doing this reduces the force of contact on your hand principally because the Group of answer choices force of contact is reduced relative velocity is less time of contact is increased time of contact is decreased none of these
Answer:
C: time of contact is increased
Explanation:
When a ball is falling from height, it maintains the same mass but velocity may change depending on the conditions in that environment.
Now, to catch the ball on your palm, you need to find a way to reduce the momentum of the ball upon hitting your hand.
Now, to reduce the momentum, we need to apply impulse.
This is because we know that;
Impulse(I) = F × t = change in momentum (m(v - u))
Thus;
I = Ft
F = I/t
We are told that extending the hand reduces the force of contact on your hand.
Thus;
For F which is the force to be reduced, the denominator (t) has to be increased.
Thus, the correct answer is that time of contact is increased
Question 1 of 10
Through which process is fertile soil renewed?
A. Reproduction
B. The water cycle
C. Precipitation
D. Nutrient cycling
SUBMIT
Answer:
soil fertility...
Explanation:
none of these answers.. really go with that that question the best choice and real answer to your question is soil fertility
Answer: D.Nutrient cycling
The summer camps had a field trip from the campus to Fragrance Hill. They traveled at an average speed of 65 km/h in the first 2 hours. After that, traveled at another average speed of 78 km/h. If the distance between the campus and Fragrance Hill is 364 km, what was the total time for the field trip?
Answer:
Explanation:
They traveled this distance in 2 parts, essentially. Part 1 had an average speed for a certain number of hours, part 2 had an average speed for a certain number of hours, and those 2 parts taken together took them a distance of 364 km. In equation form, that looks like this:
km/hr part 1 + km/hr part 2 = 364 km
Now we need to find each part on the left side of that equation. Part 1 first:
We traveled 65 km/hr for 2 hours, so that took us
[tex]65\frac{km}{hr}*2hr[/tex] and canceling out the hour label, we have that in part 1 we got
65(2) = 130 km. Good. Now onto the second part, where our unknown is.
We traveled 78 km/hr the second part for x hours, so that took us
[tex]78\frac{km}{hr}*xhr[/tex] and canceling out the hour label, we have that in part 2 we got
78x km. Now we can fill in the main equation (the one in bold print)
130 km + 78x km = 364 km and subtracting 130 km from both sides:
78x km = 234 km and dividing by 78 km:
x = 3 hours. Part 2 took 3 hours. Part 1 took 2 hours, so the whole trip took 5 hours.
The mass of a brick is 2kg. Find the mass of water displaced by it when it is completely immersed in water. (Density of the bricks is 2.5 g/cm^3)
Answer:
2000g
Explanation:
volume=mass/density
=2000/2.5
=800cm³
mass=density×volume
=800×2.5
=2000g
8. Which explains how a plane mirror works?
Light rays reflect off an object, strike the mirror, and are reflected into your eyes.
The mirror absorbs light, and then displays virtual images of an object.
The object emits a ray of light, which strikes the mirror, and is reflected back to the object.
Answer:
light rays reflect off an object ,strike the mirror ,and are reflected into your eyes
What is the S.I Unit of electric flux?
Answer:
Volt metre (Vm)
or Newton/Coulomb x (Metre)^2 (N/C x m^2)
You throw a water balloon straight up with a velocity of 14 m/s. What is ite maximum height?
A. 12.9 m
B. 10.0 m
C 11.6 m
D. 13.7 m
Answer:
The maximum height is 10.0m
The correct option about the free fall motion is "10 m".
What is free fall motion?A vertically oriented uniformly accelerated motion is referred to as "free-fall" motion. We refer to a vertical movement of an object either upward or downward as being in free fall.
What are the three equations of motion under uniform acceleration?v = u + at ----------1)s = ut + (1/2)at² ----------2)v² - u² = 2as ----------3)How to solve this question?We have given initial velocity (u) as 14 m/s
and we have to find out the maximum height (s)
We know that at maximum height the final velocity (v) will become 0
and acceleration will always be act toward downward
with the value of g = 9.8 m/s²
Applying the first equation
0 = 14 - 9.8t
9.8t = 14
t = 14/9.8 seconds
t = 1.4 seconds
Applying the second equation
s = 14 × 1.4 + ( (1/2) × (-10) × (1.4)² )
s = 19.6 - ( 5 × 1.96 )
s = 19.6 - 9.8
s = 9.8 m
s ≈ 10 m
Thus, we can conclude that if we throw a water balloon straight up with initial velocity of 14 m/s then the balloon will attain the maximum height of 10 m.
Learn more about free fall here:
https://brainly.com/question/14732889
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A light spring with force constant 3.05 N/m is compressed by 7.80 cm as it is held between a 0.400-kg block on the left and a 0.800-kg block on the right, both resting on a horizontal surface. The spring exerts a force on each block, tending to push the blocks apart. The blocks are simultaneously released from rest. Find the acceleration with which each block starts to move, given that the coefficient of kinetic friction between each block and the surface is 0, 0.035, and 0.397. (Let the coordinate system be positive to the right and negative to the left. Indicate the direction with the sign of your answer. Assume that the coefficient of static friction is the same as the coefficient of kinetic friction. If the block does not move, enter 0.)
Complete Question
A light spring with force constant 3.05 N/m is compressed by 7.80 cm as it is held between a 0.400-kg block on the left and a 0.800-kg block on the right, both resting on a horizontal surface. The spring exerts a force on each block, tending to push the blocks apart. The blocks are simultaneously released from rest. Find the acceleration with which each block starts to move, given that the coefficient of kinetic friction between each block and the surface is 0, 0.035, and 0.397. (Let the coordinate system be positive to the right and negative to the left. Indicate the direction with the sign of your answer. Assume that the coefficient of static friction is the same as the coefficient of kinetic friction. If the block does not move, enter 0.)
(a) u = 0 heavier block m/s2 m/s2 lighter block
(b)M = 0.035 heavier block m/s2 m/s2 lighter block
Answer:
a) [tex]A_h=0.297[/tex]
[tex]A_l=-0.59475[/tex]
b) [tex]a=0[/tex]
[tex]a=-0.25175m/s^2[/tex]
Explanation:
From the question we are told that:
Force constant [tex]k=3.05N/m[/tex]
Compression Length [tex]l_c=7.80cm=0.07m[/tex]
Left Mass [tex]M_l=0.400kg[/tex]
Right Mass [tex]M_r=0.800kg[/tex]
Coefficient of kinetic friction [tex]\mu=0, 0.035, and\ 0.397.[/tex]
Therefore
Spring force is given as
[tex]F_s=Kx[/tex]
[tex]F_s=3.05*0.070[/tex]
[tex]F_s=0.238N[/tex]
Generally the equation for Acceleration is mathematically given by
[tex]A=\frac{F}{m}[/tex]
For Heavier block
[tex]A_h=\frac{F_s}{m_r}[/tex]
[tex]A_h=\frac{0.238N}{0.8}[/tex]
[tex]A_h=0.297[/tex]
For Lighter blocks
[tex]A_l=\frac{F_s}{m_r}[/tex]
[tex]A_l=\frac{-0.238N}{0.4}[/tex]
[tex]A_l=-0.59475[/tex]
b)
Generally the equation for Force is mathematically given by
[tex]F_s-F=ma[/tex]
For Heavier block
[tex]F>Fs[/tex]
Therefore
[tex]a=0[/tex]
For Lighter blocks
[tex]F-F_s=ma[/tex]
[tex](0.035)(0.4)(9.8)-(0.2379)=(0.4)a[/tex]
[tex]a=-0.25175m/s^2[/tex]
A hydraulic jack is used to lift a car by applying a force of 120 N at the pump piston.
If the area of the ram and pump piston are 100 cm2 and 1m2 respectively:
(i)Calculate the force that is applied to the ram.
Answer:
I don't know.. sorry
Explanation:
help u next time
What observation related to spectral lines from distant galaxies provides
evidence for the big bang theory?
A. They appear just as they do on Earth.
B. They are shifted toward the blue end of the spectrum.
C. They fail to shift into the ultraviolet region.
O 0
D. They are shifted toward the red end of the spectrum.
They are shifted toward the red end of the spectrum.
efficiency of a lever is always less than 100%. give reason.
Answer:
Answer: mechanical advantage is always less than velocity ratio due to friction. So the efficiency of a machine is always less than 100%.
22) How is it possible to fill medicine in a syringe?explain
I hope this helps you ^-^
4. Write any three differences between single fixed pulley and single moveable pulley .
Thanks to correct answer.
Brainliest to Best answer.
Report to random and unexplained answers. ✌️♥️..
Answer:
Write any three differences between single fixed pulley and single moveable pulley.
Single fixed pulley;
Pulley do not go up and down.This pulley has a fixed axis of rotation. The load is attached to one end of the rope. Only the direction of the force is changed, not the magnitude.Single moved pulley;
Pulley move up and down.The axis of rotation of this pulley is not fixed. The load is attached to the pulley.The direction of the force as well as the magnitude of force change.