Regents Physics 2

Question 1

A car traveling at 20 m/s applies its brakes and comes to rest in 4 seconds. What is the magnitude of the car's acceleration?

Accepted Answer

5 m/s²

Answer

Acceleration = Δv/Δt = (0 − 20)/4 = −5 m/s², so the magnitude is 5 m/s².

Question 2

Which of the following best describes a scalar quantity?

Accepted Answer

Speed

Answer

Speed has magnitude only (no direction), making it a scalar, while velocity, displacement, and force are vectors.

Question 3

A 5 kg object is acted upon by a net force of 15 N. What is its acceleration?

Accepted Answer

3 m/s²

Answer

Newton's second law: a = F/m = 15/5 = 3 m/s².

Question 4

An object is thrown horizontally from a cliff. Which component of its velocity increases as it falls?

Accepted Answer

Vertical

Answer

Gravity accelerates the object downward, increasing the vertical component; horizontal velocity remains constant (ignoring air resistance).

Question 5

Two objects with charges +2 μC and −2 μC are placed 0.1 m apart. Compared to the force on the positive charge, the force on the negative charge is:

Accepted Answer

Equal in magnitude but opposite in direction

Answer

Newton's third law applies to electrostatic forces: the forces are equal in magnitude but opposite in direction.

Regents Practice Test