A CONSTANT FORCE ACTS ON AN OBJECT OF MASS 5KG FOR A DURATION OF 2 SEC .IT INCREASES THE OBJECTS VELOCITY FROM 3M/S TO 7M/S .FIND THE FORCE APPLIED

Question

FORCE AND LAWS OF MOTION

CLASS-9TH 

CBSE BOARD DELHI INDIA

Answer 1

Hi Meraz!

 

By Newton's 2nd law of motion, the net force on an object equals its mass times its acceleration.

 

What is the acceleration on this object?  Acceleration is defined to be change in velocity over change in time.  This object changes velocity from 3 m/s to 7 m/s in 2 seconds.  Hence:

 

a = (v_f-v_i)/Δt = (7 m/s - 3 m/s)/(2 s) = 4/2 = 2 m/s²

 

Then, F_net = ma = (5 kg)(2 m/s²) = 10 N

 

Hope this helps!