OAR OAR Mechanical Comprehension: Forces 3

Question 1

A 4 kg object is suspended by two ropes that each make a 45° angle with the ceiling. What is the tension in each rope? (g = 10 m/s²)

Accepted Answer

28.3 N

Answer

20 N

Answer

40 N

Answer

14.1 N

Question 2

Which of Newton's laws states that for every action there is an equal and opposite reaction?

Accepted Answer

Third Law

Answer

First Law

Answer

Second Law

Answer

Law of Universal Gravitation

Question 3

A car of mass 1,200 kg decelerates from 20 m/s to rest in 4 seconds. What braking force was applied?

Accepted Answer

6,000 N

Answer

4,800 N

Answer

300 N

Answer

240 N

Question 4

Which type of friction acts on an object that is already in motion across a surface?

Accepted Answer

Kinetic friction

Answer

Static friction

Answer

Rolling friction only

Answer

Normal friction

Question 5

A 60 N force is applied at an angle of 60° above the horizontal to push a box. What is the horizontal component of this force?

Accepted Answer

30 N

Answer

51.96 N

Answer

60 N

Answer

34.64 N

Question 6

What happens to the normal force on an object resting on a horizontal surface when a downward vertical force is added?

Accepted Answer

Normal force increases

Answer

Normal force decreases

Answer

Normal force remains the same

Answer

Normal force becomes zero

Question 7

A 5 kg block on a frictionless surface is pushed by two horizontal forces: 20 N east and 10 N west. What is the magnitude of the block's acceleration?

Accepted Answer

2 m/s²

Answer

6 m/s²

Answer

4 m/s²

Answer

1 m/s²