AP Physics Physics: Classical Mechanics & Kinematics 2

Question 1

A projectile is launched at 30° above the horizontal with an initial speed of 20 m/s. What is the maximum height reached? (g = 10 m/s²)

Accepted Answer

5 m

Answer

The vertical component is 20sin(30°) = 10 m/s; max height = v²/(2g) = 100/20 = 5 m.

Question 2

A 5 kg block slides down a frictionless incline of angle 37°. What is the block's acceleration? (g = 10 m/s², sin37° ≈ 0.6)

Accepted Answer

6 m/s²

Answer

On a frictionless incline, a = g·sinθ = 10 × 0.6 = 6 m/s².

Question 3

Two objects with masses 2 kg and 4 kg experience the same net force. What is the ratio of their accelerations (a₂ kg / a₄ kg)?

Accepted Answer

2:1

Answer

From F = ma, acceleration is inversely proportional to mass, so a₂/a₄ = m₄/m₂ = 4/2 = 2:1.

Question 4

A car traveling at 20 m/s decelerates uniformly and stops in 4 seconds. What distance does it travel while stopping?

Accepted Answer

40 m

Answer

Using d = (v₀ + v)/2 × t = (20 + 0)/2 × 4 = 40 m.

Question 5

Which of the following correctly describes the velocity of an object in uniform circular motion?

Accepted Answer

Constant in magnitude, changing in direction

Answer

In uniform circular motion, speed (magnitude of velocity) is constant but direction continuously changes.

AP Practice Test