OAR OAR Mechanical Comprehension: Forces 5

Question 1

A hydraulic press has an input piston of area 0.01 m² and an output piston of area 0.1 m². If an input force of 50 N is applied, what is the output force?

Accepted Answer

500 N

Answer

5 N

Answer

50 N

Answer

5,000 N

Question 2

Which statement correctly describes the relationship between mass and weight?

Accepted Answer

Weight is the force of gravity on an object; mass is the amount of matter

Answer

Mass and weight are the same physical quantity

Answer

Mass changes with location; weight does not

Answer

Weight is measured in kilograms; mass in Newtons

Question 3

An object is pulled by a 100 N force at 37° above the horizontal on a rough floor (μk = 0.3). The object weighs 200 N. What is the normal force from the floor?

Accepted Answer

139.8 N

Answer

200 N

Answer

260.2 N

Answer

140.2 N

Question 4

A 20 kg box accelerates at 3 m/s² on a surface with kinetic friction. If the applied horizontal force is 100 N, what is the friction force?

Accepted Answer

40 N

Answer

60 N

Answer

20 N

Answer

100 N

Question 5

A hanging sign is supported by two cables: one horizontal and one at 60° above horizontal. If the sign weighs 120 N, what is the tension in the angled cable?

Accepted Answer

138.6 N

Answer

60 N

Answer

104 N

Answer

120 N

Question 6

What is the principle of superposition as it applies to forces?

Accepted Answer

The net force equals the vector sum of all individual forces acting on an object

Answer

Forces cannot act simultaneously on an object

Answer

Larger forces always cancel smaller ones

Answer

Forces must be parallel to be added together

Question 7

A 15 kg sled is pulled across snow with 60 N of tension in a rope held at 20° above horizontal. If μk = 0.1 and g = 10 m/s², what is the friction force? (sin 20° ≈ 0.34, cos 20° ≈ 0.94)

Accepted Answer

12.54 N

Answer

15 N

Answer

14.49 N

Answer

6 N