Question

If a man speeds up by 1 m/s. his kinetic energy increases by 44%. His original speed in m/s is
(1) 1
(2) 2
(3) 5
(4) 4​

Answer 1

Answer:

5 m/s

Explanation:

1) Let the original speed be 'v' m/s .

Then, Final Speed, = (v+1)

Since, Kinetic Energy is proportional to square of speed,

That is,

$\frac{(v+1)^2-v^2}{v^2}=0.44\\ \\=>\frac{(v+1)^2}{v^2}-1=0.44\\ \\=> \frac{(v+1)^2}{v^2}=1.44\\ \\ =>\frac{(v+1)}{v}=1.2 \\ \\=> v=5 m/s$

Hence, Original Speed is 5 m/s

Answer 2

Answer:

Explanation:

Option (3)