Question

1. Define acceleration and state its SI unit. For motion along a straight line, when do we consider the acceleration to be (i) positive (ii) negative? Give an example of a body in uniform acceleration. 2. Find the total displacement of the body from the following graph: 3. A car travels at 54 km/h for first 20 s, 36 km/h for next 30 s and finally 18 km/h for next 10 s. Find its average speed. 4. Define acceleration and give its SI unit. When is acceleration of a body negative? Give two examples of situations in which acceleration of the body is negative. 5. Distinguish between uniform motion and non, uniform motion. Is uniformly accelerated motion uniform motion? Give one example each of uniform and non-uniform motion. 6. The speedometer readings of a car are shown below. Find the acceleration of the car and its displacement. Time Speedometer 9:25 am 9:45 am 36 km/h 72 km/h 7. Define uniform circular motion and give example of it. Why is it called accelerated motion?

Answer 1

Answer:

The SI unit of acceleration is meter per second square. The acceleration is said to be positive when acceleration is in the same direction and when it is in the opposite direction we say that acceleration is negative. The motion a freely falling body is an example of body moving with uniform acceleration.