Unbalanced Forces Review

A 80 kg skydiver is free falling at a constant velocity of 19 m/s. What is the net (total) force acting on her?

• 1,520 N
• 0 N
• 4.21 N
• Not enough information to answer

A 1.5 kg book is pushed across the table, which has a coefficient of friction of 0.45. Calculate the force due to friction.

• 6.6 N

• 0.66 N

• 6.6 g

• 3.33 N

the force due to friction on a bike tire is 70 N. If the coefficient of friction of the road is 0.78, what is the mass of the bike?

• 89.7
• 9.1 N

• 9.1 kg

• 54.6 kg

 What is the force of friction between a block of ice that weighs 950 N and the ground if μ = .12? 

• 65 N
• 226 N
• 175 N
• 114 N

  A 220 Kg crate is pushed horizontally with a force of 700 N. If the coefficient of kinetic friction is 0.20, calculate the acceleration of the crate.   

• 1.02 m/s²
• 1.22 m/s²
• 1.42 m/s²
• 1.62 m/s²

What is the coefficient of static friction if it takes 44 N of force to move a box that weighs 86 N? 

• 0.78
• 0.51
• 0.78 N
• 0.58 N

What are the units on the coefficient of friction?

• none
• Newtons
• meters
• kilograms

What are the units on the force due to friction?

• none
• Newtons
• meters
• kilograms

A man standing on a scale in an elevator notices that the scale reads 40 newtons greater than his normal weight. Which type of movement of the elevator could cause this greater-than-normal reading?

• accelerating upward

• accelerating downward

• moving upward at a constant speed

• moving downward at a constant speed

A rubber band pulls a 1 kg block at 3 m/s^2. An identical one accelerates at 5 m/s^2. What is the mass of the second block?

• 0.6 kg
• 1 kg
• 2 kg
• 0.01 kg