Question
A constant force acting on a body of mass 3.0 kg changes its speed from 2.0 m s–1 to 3.5 m s–1 in 25 s. The direction of the motion of the body remains unchanged. What is the magnitude and direction of the force?
Solution
Given,
Mass of the body, m = 3 kg
Initial speed of the body, u = 2 m/s
Final speed of the body, v = 3.5 m/s
Time, t = 25 s
Using the first equation of motion,
v = u + at
Acceleration(a) produced in the body, a =
Therefore,
Now, according to Newton's second law of motion, we have
F = ma
= 3 x 0.06
= 0.018 N
Since the application of force does not change the direction of the body, the net force acting on the body is in the direction of its motion.
Mass of the body, m = 3 kg
Initial speed of the body, u = 2 m/s
Final speed of the body, v = 3.5 m/s
Time, t = 25 s
Using the first equation of motion,
v = u + at
Acceleration(a) produced in the body, a =
Therefore,
Now, according to Newton's second law of motion, we have
F = ma
= 3 x 0.06
= 0.018 N
Since the application of force does not change the direction of the body, the net force acting on the body is in the direction of its motion.
