AP Physics Physics: Classical Mechanics & Kinematics 4

Question 1

A satellite orbits Earth at constant speed in a circular orbit. Which statement correctly describes its motion?

Accepted Answer

Gravity provides centripetal force toward Earth's center

Answer

Gravity acts as centripetal force pulling the satellite toward Earth's center, causing circular orbital motion.

Question 2

On an Atwood machine, masses of 3 kg and 5 kg are connected by a massless string over a frictionless pulley. What is the system's acceleration? (g = 10 m/s²)

Accepted Answer

2.5 m/s²

Answer

For an Atwood machine, a = (m₂−m₁)g/(m₁+m₂) = (5−3)(10)/(3+5) = 20/8 = 2.5 m/s².

Question 3

A position-time graph shows a straight line with a negative slope passing through the origin. What does this indicate?

Accepted Answer

The object moves at constant velocity in the negative direction

Answer

A straight line on a position-time graph means constant velocity; a negative slope means the object moves in the negative direction.

Question 4

A 2 kg object is dropped from rest and falls for 3 s. Neglecting air resistance, what is its speed just before impact? (g = 10 m/s²)

Accepted Answer

30 m/s

Answer

Using v = v₀ + at = 0 + 10(3) = 30 m/s.

Question 5

An object travels in a straight line with increasing speed in the positive direction. Which combination correctly describes its velocity and acceleration?

Accepted Answer

v > 0, a > 0

Answer

Increasing speed in the positive direction means both velocity and acceleration are positive.

AP Practice Test

AP Practice Test

AP Physics Physics: Classical Mechanics & Kinematics 4