Physics Exam Questions

A car is travelling along a level road at a steady speed. Fig. 1.1 shows the speedometer in the car. A speedometer registers how fast the car is going. (a) How far, in km, does the car travel in ½ hour at the speed shown in Fig. 1.1?

(b) (i) On the axes shown in Fig. 1.2, draw a line representing the motion of the car for the ½ hour mentioned in (a). Do not go beyond ½ hour.

(ii) At the end of the ½ hour, the car reaches a region where the road begins to rise up into some mountains. The car climbs the mountains for a further ½ hour. During the climb, its speed steadily decreases to 30 km / hour. The driver then stops the car so that he can admire the view. On Fig. 1.2, draw a line representing the climb and the stopping of the car.

A student carries out an experiment to find the density of water, using a method that is slightly different from normal. In his method, he starts with a measuring cylinder containing some water, and then adds more water to that already in the measuring cylinder. His experiment is illustrated in Fig. 2.1. The readings he obtains are as follows: reading 1 53 cm³ reading 2 84 cm³ reading 3 205 g reading 4 238 g Calculate (a) the volume of the added water.

(b) the mass of the added water.

(c) the density of water, stating clearly the equation you are using.

A train is passing through a station at constant speed, as shown in Fig. 3.1. The engine produces a forward thrust of 70 000 N. There is a 25 000 N force opposing the motion, due to friction in the wheels. (a) Mark these forces on Fig. 3.1, using an arrow labelled 70 000 N and an arrow labelled 25 000 N.

(b) The train is travelling at constant speed, so there must be another horizontal force acting on it. (i) State the direction of this force.

(ii) Calculate the size of this force.

(iii) Suggest what might be causing this force.