Dynamics for 3G2

A car is accelerating along a road in the direction shown. The wheel shown is connected to the engine. In which direction is the force of friction exerted by the road on the car tyre?

• A

• B

• C

• D

The speed-time graph shown is for a model car. The resultant force on the car is 0.60 N. What is the mass of the car?

• 0.060 kg

• 0.20 kg

• 1.8 kg

• 5.4 kg

Four forces, P, Q, R, and S, act on an object. The directions of the forces are shown. The object moves vertically upwards with a constant speed. Which statement must be correct?

• P and Q are of same magitude

  R and S are of same magnitude

• P and R are equal in magnitude but both are larger than Q or S.

• Q and S are equal in magnitude but P is larger than R.

• Q and S are equal in magnitude and P and R are equal in magnitude

Which free body diagram shows the directions of the forces acting on a rocket travelling vertically upwards?

• A

• B

• C

• D

A car is moving forward. Two forces act on the car as shown. When force F equals force R, which statement is correct?

• The car is moving with non-uniform acceleration.

• The car is moving with uniform acceleration.

• The car is moving with uniform velocity.

• The car is stopping.

A box of mass 50 kg is pushed across a floor with a force of 340 N. The total frictional force acting on the box is 320 N. What is the acceleration of the box?

• 0.40 m/s²

• 2.5 m/s²

• 6.4 m/s²

• 6.8 m/s²

A large wooden crate of mass 160 kg is pushed across a rough floor with a force of 240 N. The acceleration of the crate is 0.50 m/s². What is the frictional force on the crate?

• 80 N

• 120 N

• 160 N

• 1600 N

A block of mass 5 kg is pushed along a road with a force if 30 N. The frictional force is 10 N. What is the acceleration of the block?

• 2.0 m/s²

• 4.0 m/s²

• 6.0 m/s²

• 8.0 m/s²

A block of mass 5 kg is pushed along a road with a force if 30 N. The frictional force is 10 N. What is the acceleration of the block?

• 2.0 m/s²

• 4.0 m/s²

• 6.0 m/s²

• 8.0 m/s²

A deep-sea diver is sinking into deep water at a constant speed of 0.5 m/s. What is the resultant force acting on the diver, if he, together with his diving gear, has a total mass of 100 kg?

• 0 N

• 100 N downwards

• 1000 N downward

• 1000 N upwards