Physics Quiz

Describe fully the forces shown in the diagrams (a), (b), (c) and (d).

What is the weight-force exerted by a mass of 51 kg? (Use g = 9.8 m/s².)

Two equal masses of 10.2 kg each are suspended by a light rope over a pulley, which is hanging on a chain. The pulley has a mass of 0.51 kg. (a) What is the tension in the rope? (b) What is the tension in the chain? (Use g = 9.8 m/s².)

If a shoe has an area of 15 000 mm² in contact with the floor, what is the average pressure exerted on the floor by a boy with a mass of 60 kg standing normally? (Use g = 10 m/s².)

What is the SI unit of force? What other units can be used? Why is it incorrect to use the old gravitational unit, kg f?

Describe two effects of a force. Explain the relationship between mass and weight-force. How can the mass of a body change? How can the weight-force of a body change?

What is the weight-force produced by masses of 1 kg; 10 kg; 10.2 kg; 27.3 kg; 2000 kg? (Use g = 9.8 m/s² first; then use g = 10 m/s².)

Suggest values for g suitable for use in each of the following calculations. Justify your answer. (i) Time taken for a pencil to fall from the desk to the floor. (ii) Time taken for a stone to fall down a deep mine shaft. (iii) Thickness of a suspended concrete floor slab. (iv) Tension in a crane cable. (v) Time of rocket burn for a satellite launch.

A bag containing 10 apples is hung from a spring balance which then shows a reading of 1 kg. What force is the hook supporting?

Completely describe the force acting on each anchor bolt holding the ends of a suspended cable if the tension in the cable is 5 kN.