# Questions on Forces

Q6. In a storm, a small ship was blown onto a beach. Now it is calm and there is no wind. A tugboat is trying to pull the ship off the beach.

(a) The tugboat pulls the ship with a force of 25 000 N. The ship does not move because of the force of friction acting on it.

(i) What is the size of the frictional force acting on the ship?

 A zero B more than zero but less than 25 000 N C 25 000 N D more than 25 000 N

1 mark

(ii) Add an arrow to the drawing to show the direction of the frictional force acting on the ship.

1 mark

(b) When the tide is higher, the tugboat again pulls the ship with a steady force of 25 000 N. The ship begins to move.

Once the ship is off the beach, the tugboat continues to pull the ship with a force of 25 000 N. A frictional force due to the water acts on the ship.

(i) At first, the speed of the ship increases.

Which of the following best describes the frictional force acting on the ship while its speed is increasing.

 A zero B more than zero but less than 25 000 N C 25 000 N D more than 25 000 N

1 mark

(ii) After a short while, the ship reaches a steady speed. The tugboat continues to pull with a force of 25 000 N.

which of the following best describes the frictional force acting on the ship while it is going at a steady speed.

 A zero B more than zero but less than 25 000 N C 25 000 N D more than 25 000 N

1 mark

(iii) The ship is towed to the north. What is the direction of the frictional force acting on the ship?

1 mark

Maximum 5 marks