PHYSICS KSSM F5 (LO 1.1-1.2)

Diagram 1 shows an object of 20 kg is pushed by a force of 50 N.

If the object accelerate with 2.0 m s^–2, what is the frictional force of the rough surface on the object, in N?

• 10

• 25

• 40

• 50

          Diagram 2 shows a constant force, F acts on a wooden block placed on a smooth surface. The wooden block will move with

• constant velocity

• uniform acceleration

• gradually increasing acceleration

Which of the following systems will produce maximum acceleration on the          object?

• 
• 
• 
• 

A force of 100 N pulls a load of 6 kg where it is suspended on a smooth pulley as shown in Diagram 3.

What is acceleration of the load?

• 60 m s^–2

• 6.7 m s^–2

• 10 m s^–2

• 17 m s^–2

Which of the following graphs shows the relationship between mass and acceleration when constant force applied?

• A

• B

• C

• D

Diagram 4 shows a boy of 40 kg stands on a lift moving with acceleration 1.5 m s^–2.

What is the force acting on the floor of the lift due to the mass of the boy?

• 340 N

• 400 N

• 427 N

• 460 N

Diagram 5 shows a force, F pulling a 3 kg wooden block horizontally on a smooth and flat surface. The wooden block and load of 4 kg tied by a string.

          If the load accelerates with 2 m s^–2 upward, what is the magnitude of F?

• 8.0 N

• 40 N

•           48 N

• 84 N

Diagram 6 shows a poster of 1.2 kg hanging on a wall by a rope at an angle of 40° to the vertical.

What is the tension of the rope?

• 4.6 N

• 6.0 N

• 7.8 N

• 9.3 N

Diagram 7 shows a 10 kg load is suspended by two threads.

What is the tension of Thread 1?

• 50.0 N

• 64.0 N

• 131 N

• 156 N

Diagram 8 shows a box resting on an inclined plane at angle θ to the vertical.

There are three forces acting on the box. By using m for mass of the box, g for the acceleration due to gravity, and F for frictional force, derive an equation to express the frictional force of the box on the inclined plane.

• F = mg sin θ

• F = mg cos θ

• F = mg tan θ

• F = mg cos (90 – θ)