Question

A sprinter start from rest and picks up a
speed of 25 m/s in 5 seconds.
(a) Name the type of motion
(b) Derive a relation to find the distance
travelled during ºt' second for this type of
motion
(c) A car manufacturer advertises that the
breaks are so perfect that the car stops
instantly. Do you agree ? Explain
​

Answer 1

Answer:

uniform motion

Explanation:

Answer 2

(a) It can be both:
1.Uniform motion- Covers equal distances in equal intervals of time or velocity increases in a uniform manner i.e. speed increases by 5m/s in every second.

2. Non-uniform Motion- Covers unequal distances in equal intervals of time or speed changes in a non-uniform manner i.e. 3m/s in 1st second, 4m/s in 2nd second and so on.

Theoretically it should be uniform motion, but practically in real life, it should be non-uniform motion.



(b) Distance= speed x time
=>D = 25t (here speed=25m/s and time is 't' seconds)


(c)Again thereotically it is possible but practically it isn't. This is because for the car to change its speed from x m/s to 0, it will cover a certain distance in doing so and will have a certain speed at a particular time.
As we know,
Time taken = distance covered / speed
Therefore, time cannot be zero and hence the car cannot stop instantly.

Hope it helps!!!