High School Physics practice questions and exam guide

Convert 2.5 km to meters.

1. 250 m
2. 25,000 m
3. 0.0025 m
4. 2,500 m

Answer: D — 2,500 m

D) Correct — 1 km = 1,000 m. A) Multiplies by 100. B) Multiplies by 10,000. C) Divides by 1,000.

Darts land close together but far from the bullseye. The throws are:

1. accurate but not precise
2. both precise and accurate
3. precise but not accurate
4. neither precise nor accurate

Answer: C — precise but not accurate

C) Correct — Precision is consistency; accuracy is closeness to the target. A) Reverses the two. B) They miss the target. D) They are consistent.

Ignoring air resistance, which launch angle gives a projectile the greatest range on level ground?

1. 90°
2. 30°
3. 45°
4. 60°

Answer: C — 45°

C) Correct — It balances horizontal and vertical motion. A) Goes straight up and lands at the start. B) Gives less range than 45°. D) Gives the same range as 30°.

Forces of 10 N to the right and 4 N to the left act on a cart. What is the net force?

1. 14 N to the right
2. 6 N to the right
3. 6 N to the left
4. 40 N to the right

Answer: B — 6 N to the right

B) Correct — Opposite forces subtract. A) Adds forces in opposite directions. C) Gets the direction wrong. D) Multiplies.

A motor does 600 J of work in 3 s. What is its power?

1. 1,800 W
2. 200 W
3. 0.005 W
4. 603 W

Answer: B — 200 W

B) Correct — P = W/t = 600/3. A) Multiplies. C) Divides time by work. D) Adds.

What is the momentum of a 3 kg ball moving at 4 m/s?

1. 24 kg·m/s
2. 0.75 kg·m/s
3. 12 kg·m/s
4. 7 kg·m/s

Answer: C — 12 kg·m/s

C) Correct — p = mv. A) Uses ½mv² = 24 J, which is kinetic energy. B) Divides. D) Adds.

If the distance between two masses doubles, the gravitational force between them becomes:

1. half as large
2. twice as large
3. four times as large
4. one-fourth as large

Answer: D — one-fourth as large

D) Correct — F ∝ 1/r². A) Treats F as ∝ 1/r. B) Gets the direction wrong. C) Inverts the relationship.

When two waves meet crest to crest, the result is:

1. destructive interference
2. constructive interference
3. refraction
4. the Doppler effect

Answer: B — constructive interference

B) Correct — The amplitudes add. A) Happens crest to trough. C) Is bending. D) Involves a moving source.

A converging lens has f = 10 cm. An object is 30 cm away. Where is the image?

1. 20 cm
2. 15 cm from the lens
3. 7.5 cm
4. 40 cm

Answer: B — 15 cm from the lens

B) Correct — 1/dᵢ = 1/10 − 1/30 = 2/30. A) Subtracts the distances. C) Adds the reciprocals. D) Adds the distances.

A 12 V battery is connected to a 4 Ω resistor. What current flows?

1. 48 A
2. 0.33 A
3. 3 A
4. 16 A

Answer: C — 3 A

C) Correct — I = V/R = 12/4. A) Multiplies V and R. B) Divides R by V. D) Adds.

The north end of a compass needle points toward geographic north because:

1. Earth's magnetic north pole is near geographic north
2. Earth's magnetic south pole is near geographic north
3. the needle is pulled by the North Star
4. the needle is pulled by gravity

Answer: B — Earth's magnetic south pole is near geographic north

B) Correct — Opposite poles attract. A) Would repel the needle's north end. C) Stars don't affect compasses. D) Gravity doesn't orient compasses.

Gamma rays are:

1. helium nuclei
2. high-energy electromagnetic radiation
3. fast electrons
4. slow neutrons

Answer: B — high-energy electromagnetic radiation

B) Correct — They have no mass or charge. A) Are alpha particles. C) Are beta particles. D) Are not gamma rays.

State the work-energy theorem.

The net work done on an object equals its change in kinetic energy: W_net = ΔKE.

What is diffraction?

The bending of waves around obstacles or through openings; most noticeable when the opening size is comparable to the wavelength.

What is electric charge measured in?

Coulombs (C).

What is inertia?

An object's resistance to changes in its state of motion. Mass is a measure of inertia.

Nuclear fission vs fusion?

Fission splits a heavy nucleus, such as uranium-235, into lighter ones; fusion joins light nuclei, such as hydrogen, into heavier ones. Both release energy because the products have less mass (E = mc²). Fission powers nuclear reactors; fusion powers the Sun.

What is the difference between distance and displacement?

Distance is the total path length traveled (scalar). Displacement is the straight-line vector from start to end position.