Question

An Athlete running with a speed of 300m/s after 20 second his speed become 8m per second then calculate work done by a
personacceleration of a person distance moved by a person.​

Answer 1

Explanation:

Answer

The situation is shown in Fig. 

Fig.

For motion between times t=0 and t2 :

u=0,a=2 ms−2,s=900 m,v=v2 (say)

As v2−u2=2as

∴v22−02=2×2×900 or v2=60 ms−1

Time, t2=av−u=260−0=30 s.

For motion between times t2 and t3 : This motion ???? at a constant speed of 60 ms−1.

∴ Time taken, t3−t2=601500−900=10 s

For motion between time t=0 and t1 :

u=0,s=750 m,a=2 ms−2,t=t1