Question

a motor car moving with a velocity of 54km/hr is brought to rest in 1)5sec and 2)30m. find the retardation in each case​

Answer 1

Answer:

1. a=-3m/sec²
2. a=3.75m/sec²

Explanation:

we can simply use two equation of motion to solve this type of questions.

• first, Newton's first equation of motion is.

V=U+at.

0= (54*5)/18 + a5

a= -3 m/sec²

• third equation of motion is.

2as = V² - U²

a = -U²/2s

a = - (15*15)/2*30

a = - 3.75 m/sec²