A constant retarding force of 80 N is applied to a body of mass 50 kg which is moving initially with a speed of 20 m/s . What would be the time required by the body to come to rest?

Question

A constant retarding force of 80 N is applied to a body of mass 50 kg which is moving initially with a speed of 20 m/s . What would be the time required by the body to come to rest? (A)  15 s  (B)  14 s  (C)  12.5 s  (D)  18 s

Tardigrade Admin · Accepted Answer

Here, a=(F/m)=(80/50)=1.6 m/s2 u=20 m/s and v=0 From v=u+at 0=20-1.6× t t=(20/16)=12.5 s

Q. A constant retarding force of $80 N$ is applied to a body of mass $50 k g$ which is moving initially with a speed of $20 m / s$ . What would be the time required by the body to come to rest?

$15 s$

$14 s$

$12.5 s$

$18 s$

Here, $a = \frac{F}{m} = \frac{80}{50} = 1.6 m / s^{2}$
$u = 20 m / s$ and $v = 0$
From $v = u + a t$
$0 = 20 - 1.6 \times t$
$t = \frac{20}{16} = 12.5 s$

Q. A constant retarding force of 80N is applied to a body of mass 50kg which is moving initially with a speed of 20m/s . What would be the time required by the body to come to rest?

15s

14s

12.5s

18s