1.A mass m = 20 kg is moving along a surface with coefficient of kinetic friction mk = 0.3.(adsbygoogle = window.adsbygoogle || []).push({});

A)What is the force of kinetic friction on the mass?

2.A wooden block of mass m = 9 kg starts from rest on an inclined plane sloped at an angle q from the horizontal. The block is originally located 5m from the bottom of the plane.

a)If the block, undergoing constant acceleration down the ramp, slides to the bottom in t = 2 s, and q = 30°, what is the magnitude of the kinetic frictional force on the block?

3A block of mass m1 = 2 kg and a block of mass m2 = 3 kg are tied together and are pulled from rest across the floor by a force of Fp = 21 N. The coefficient of friction of the blocks with the floor is µ = 0.13.

a) What is the acceleration of the two blocks?

a = ?m/s2

b) What is the tension in the string between the blocks?

T = N ?

4 A block of mass mblock = 1.9 kg rests on a cart of mass mcart = 3.1 kg, which moves without friction on a horizontal surface. The coefficient of static friction between the block and the cart is µ = 0.76. The cart is accelerating to the right.

a) What is the maximum acceleration such that the block does not slide on the cart?

amax = ? m/s2

b) What is the magnitude of the force on the cart required to provide the acceleration amax?

F = N ?

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: I need help with hw (my book hasnt came in yet)

**Physics Forums | Science Articles, Homework Help, Discussion**