Question

20 numerical of force and laws of motion

Answer 1

1. A farmer moves along the boundary of a square field of side 10 m in 40 s. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds ?
2. In a long distance race the athletes were expected to take four rounds of the track such that the line of finish was same as the line of start. Suppose the length of the track was 200 m
(i) What is the total distance to be covered by the athletes?
(ii) What is the displacement of the athletes when they touch the finish line?
(iii) Is the motion of the athletes uniform or non-uniform.
(iv) Is the displacement of an athlete and the distance moved by him at the end of the race equal?
3. On a 120km track, a train travels the first 30km with a uniform speed of 30km/h. How fast must the train travel the next 90km so as to average 60km/h for the entire trip ?
4. Nisha swims in a 90 m long pool. She covers 180m in one minute by swimming from one end to the other and back along the same straight path. Find the average speed and average velocity of Nisha.