Question

An object with a mass 10 kg moves at a constant velocity of 10 m/s. A constant force then acts for 4 seconds on the object giving it a speed of 2 m/ s in opposite direction. The acceleration produced is

Answer 1

Hey

initial velocity u= 10m/s

final velocity v=2m/s

time T= 4 sec

we know, F=m(v-u)/t

therefore Force=10*(2-10)/4

= -20N

we know,

F=ma

-20=10*a

a=-10m/s^2

Hope This Ans Helps

Answer 2

Initial Velocity (u) = 10m/s
Final Velocity (v) = -2m/s

Now, we need to calculate the retardation because there is decreasing velocity

$retardation = \frac{v - u}{t} \\ = \frac{ - 2 - 10}{4} \\ = \frac{ - 12m \: s ^{ - 1} }{4s} = {-3 m \: s}^{ - 2}$