I need help understanding these, please. Thanks!

Question

1. A 2 kg body moves with constant velocity when a force of 10 N is applied. What is the coefficient of kinetic friction between the table and the body? (Would I use F=m*g for this??)

2. Which of the following statements is correct for the law of conservation of energy?

a. Initial potential energy always equals to final potential energy.

b. Initial kinetic energy always equals to final kinetic energy.

c. Initial mechanical energy always equals to final mechanical energy.

d. Initial mechanical energy always equals to final mechanical energy in the absence of friction.

3. A car takes a sharp turn on a road. Which of the following provides the centripetal force on the car?

a.weight of the car

b.frictional force

c.tangential acceleration

d.gravitational force

Thanks again so much!!

Answer 1

Oh my, one by one:

1. A 2 kg body moves with constant velocity when a force of 10 N is applied. What is the coefficient of kinetic friction between the table and the body? (Would I use F=m*g for this??)
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F = m a
but a = 0
so there is no net force
10 N + Friction force = 0
so friction force = -10 N
so
10 = mu m g
mu = 10/(2*9.81)
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2. Which of the following statements is correct for the law of conservation of energy?

d. Initial mechanical energy always equals to final mechanical energy in the absence of friction.
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3. A car takes a sharp turn on a road. Which of the following provides the centripetal force on the car?
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What happens if the road is icy and the tires are bald?

b.frictional force

Answer 2

Thank you so much Damon!