Test – Homework – 1

Fig. 1.1 shows a balloon filled with helium gas.

The mass of the balloon is 120kg.

1. Calculate the weight of the balloon. Show your working.
2. The resultant force on the balloon is 54 N. Show that the acceleration of the balloon is 0.45 m/s².
3. The balloon accelerates upwards from rest at 0.45 m/s² for 8.0s. Calculate the velocity of the balloon after 8.0s.
4. Calculate the distance travelled by the balloon in the first 8.0s.

1. 1. Define pressure.
   2. Describe how pressure in a liquid varies with its depth and with its density.
2. State two energy resources for which the Sun is not the main source.
3. State and explain whether each of the following methods of electrical power generation is renewable:
   1. power generation in a nuclear power station
   2. power generation from waves in the sea

1. 1. State which state of matter, solid, liquid or gas, has the greatest thermal expansion and which has the least.
   2. Describe, in terms of the motion and arrangement of particles, the structures of solids and gases.