Question

An object is moving with velocity 10 m/s .A constant force acts for 4s on the object and it gives it a speed of 2 m/s in opposite direction.The acceleration is

Answer 1

U=velocity of a moving object=10m/s

V=speed= -2m/s  we used -2m/s because of opposition direction

time=t=4 sec

V=U + at

-2 = 10 + a×4

-2-10=4a

-12=4a

a= -3m/s²

the acceleration that is produced  is in the opposite direction same as the velocity is in opposite direction. so the object has positive acceleration,

a= -3m/s²