# Motion and Time

**1. **Classify the following as motion along a straight line, circular or oscillatory motion.

(i) Motion of your hands while running.

(ii) Motion of a horse pulling a cart on a straight road.

(iii) Motion of a child in merry-go -round.

(iv) Motion of a child on a see-saw.

(v) Motion of the hammer of an electric bell.

(vi) Motion of a train on straight bridge.

**2. ** Which of the following are not correct?

(i) The basic unit of time is second.

(ii) Every object moves with a constant speed.

(iii) Distance between two cities is measured in kilometers.

(iv) The time period of a given pendulum is not constant.

(v) The speed of a train is expressed in m/h.

**3. ** A simple pendulum takes 32 s to complete 20 oscillations. What is the time-period for the pendulum.

**4. ** The distance between two stations is 240 km. A train takes 4 hours to cover this distance. Calculate the speed of the train.

**5. ** The odometer of a car reads 57,321.0 km when the clock shows the time 8.30 AM. The odometer reading was changed to 57,336.0 km. calculate the speed of the car in km/min during this time. Express the speed in km/h also.

**6. **Salma takes 15 minutes from her house to reach her school on bicycle. If the bicycle has a speed of 2 m/s, calculate the distance between her house and the school.

**7. ** Show the shape of the distance-time graph for the motion in the following cases:

(i) A car moving with a constant speed.

(ii) A car parked on a side road.

**8. **Which of the following relations is correct?

(i) Speed = Distance × Time.

**9. **The basic unit of speed is :

(i) Km/min

(ii) m/min

(iii) km/h

(iv) m/s

**10. **A car moves with a speed of 40 km/h for 15 minutes and then with a speed of 60 km/h for the next 15 minutes. The total distance covered by the car is :

(i) 100 km

(ii) 25 km

(iii) 15 km

(iv) 10 km

**11. ** Suppose the two photograph, shown in Fig. 13.1 and Fig.13.2, had been taken at an interval of 10 seconds. If a distance of 100 meters is shown by 1 cm in these photograph, calculate the speed of the blue car.

**12. ** Fig. shows the distance-time graph for the motion of two vehicles A and B. which is one of them moving faster?

**13. ** Which of the following distance time-graph a truck moving with speed which is not constant.