Gaokao Exam Physics: Mechanics and Kinematics 2

Question 1

A car accelerates uniformly from rest to 20 m/s in 5 seconds. What is its acceleration?

Accepted Answer

4 m/s²

Answer

100 m/s²

Answer

2.5 m/s²

Answer

10 m/s²

Question 2

According to Newton's Third Law, when a horse pulls a cart forward, the cart pulls the horse backward with equal force. Why does the horse-cart system still accelerate forward?

Accepted Answer

Newton's Third Law action-reaction pairs act on different objects; the net force on the horse from the ground exceeds the backward pull from the cart

Answer

The horse exerts more force than the cart exerts back

Answer

Newton's Third Law doesn't apply during acceleration

Answer

The cart's weight cancels the backward force on the horse

Question 3

A 2 kg object slides down a frictionless incline of 30°. What is its acceleration along the incline? (g = 10 m/s²)

Accepted Answer

5 m/s²

Answer

10 m/s²

Answer

8.66 m/s²

Answer

2 m/s²

Question 4

The unit of momentum in the SI system is:

Accepted Answer

kg·m/s

Answer

kg·m/s²

Answer

N·m

Answer

J/s

Question 5

In projectile motion (抛体运动), what happens to the horizontal velocity component throughout the flight (ignoring air resistance)?

Accepted Answer

It remains constant

Answer

It increases due to gravity

Answer

It decreases due to gravity

Answer

It becomes zero at the highest point

Question 6

What does the area under a velocity-time (v-t) graph represent?

Accepted Answer

Displacement

Answer

Acceleration

Answer

Force

Answer

Distance traveled only for constant velocity

A car accelerates uniformly from rest to 20 m/s in 5 seconds.What is its acceleration?

A car accelerates uniformly from rest to 20 m/s in 5 seconds.
What is its acceleration?