Question

who will tell this I will follow him.. plss don't give wrong answer... the question is starting from the velocity ​

Answer 1

• KE = 1/2 mv²
• when velocity became half (v/2)
• KE' = 1/2 m (v/2)²
• KE' = 1/4 ( 1//2mv²)
• KE' = 1/4KE
• so kinetic decrease
• KE decrease by 3/8mv² or 3/2 KE

Answer 2

Assume,

Initial velocity as = 2v

∴ Final velocity = 2v/2 = v

Also, mass = m

$\boxed{\tt{KE = \frac{1}{2}mv^2}}$

Initial KE:-

½ (m)(2v)² = m × 2v² = 2mv²

Final KE:-

½ (m)(v)² = ½ mv²

Clearly, Final KE < Initial KE.

Difference = Initial KE - Final KE = 2mv² - ½mv² = 3/2 mv².

∴ There was a decrease in KE by 3/2 mv².