AP Physics 1 Unit 7: Oscillations practice questions

Question 1

A block on a spring gets pushed 5 cm right of center. The spring yanks it back left. Push it 10 cm right and the pull doubles. What kind of motion is this setup guaranteed to produce?

Accepted Answer

Simple harmonic motion — the restoring force is proportional to displacement. Linear F = -kx is the whole definition of SHM.

Answer

Uniform circular motion, since the block keeps returning to the same spot

Answer

Projectile motion, because the net force is constant the whole time

Answer

Any periodic motion counts as SHM regardless of how force depends on position

Question 2

A mass on a spring keeps overshooting the center and getting pulled back the other way. What's true about the net force exactly at the center point it keeps blowing past?

Accepted Answer

The net force is zero there — that's the equilibrium position. The mass has max speed but zero restoring force at that instant.

Answer

The net force is at its maximum because the mass is moving fastest there

Answer

The net force points toward the nearest endpoint to slow the mass down

Answer

There's no equilibrium position in oscillating motion

Question 3

Your friend says a pendulum swinging a full 80° back and forth is simple harmonic motion. What are they missing?

Accepted Answer

A pendulum is only SHM at small angles, where torque ∝ angle. At 80° that proportionality breaks down.

Answer

Nothing — a pendulum is SHM at any angle as long as it keeps swinging

Answer

It's only SHM if the string is massless, angle doesn't matter

Answer

Pendulums are never SHM because gravity, not a spring, drives them

Question 4

A spring pulls back harder the farther you stretch it, always toward center. Write the relationship between that restoring force and the displacement, and explain the minus sign.

Accepted Answer

F = -kx — the minus means force points opposite the displacement. It always points back toward equilibrium.

Answer

F = kx — the force pushes the object further from center as x grows

Answer

F = -kx², the restoring force grows with the square of displacement

Answer

F = mg, the restoring force is just the object's weight

Question 5

A mass hangs on an ideal spring and bounces up and down. You know the mass m and the spring constant k. How do you find the period of one full bounce?

Accepted Answer

T = 2π√(m/k) — more m lengthens it, more k shortens. Amplitude doesn't appear at all.

Answer

T = 2π√(k/m) — the mass and spring constant are swapped

Answer

T = 2π√(m/k) but you also multiply by the amplitude

Answer

T = 2π√(L/g), the same formula used for a pendulum

Question 6

You triple the mass hanging on a spring oscillator. The original period was 1.67 s. What's the new period, exactly?

Accepted Answer

It increases by a factor of √3, to about 2.89 s. Since T = 2π√(m/k), tripling m multiplies T by √3 ≈ 1.73, not by 3.

Answer

It triples to about 5.01 s, since period is directly proportional to mass

Answer

It stays at 1.67 s — mass doesn't affect period

Answer

It increases by a factor of 3² = 9, since mass is under a root

Question 7

A cart on a horizontal spring oscillates. You pull it back twice as far before releasing. What happens to the period of the motion?

Accepted Answer

Nothing — the period is unchanged; amplitude isn't in T. T = 2π√(m/k) depends only on m and k.

Answer

The period doubles since the cart has twice as far to travel

Answer

The period increases by √2, like doubling the mass would

Answer

The period is halved because the spring force is now stronger

Question 8

A grandfather clock pendulum of length L swings in small arcs at gravity g. What's the period, and what surprising thing is missing from the formula?

Accepted Answer

T = 2π√(L/g) — surprisingly, the bob's mass is missing. Period depends only on length and gravity.

Answer

T = 2π√(L/g), but heavier bobs give a longer period

Answer

T = 2π√(m/g), the period depends on the bob's mass and gravity

Answer

T = 2π√(g/L) — length and gravity are swapped

AP Physics 1 — Unit 7: Oscillations

AP Physics 1 Unit 7 practice questions

Key terms in Unit 7

Drill all of Unit 7 with spaced repetition