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?
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Answer 1

Answer:

Retarding force, F = –50 N

Mass of the body, m = 20 kg

Initial velocity of the body, u = 15 m/s

Final velocity of the body, v = 0

Using Newton’s second law of motion, the acceleration (a) produced in the body can be calculated as:

F = ma

–50 = 20 × a

∴ a = -50/20 = -2.5 ms-2

Using the first equation of motion, the time (t) taken by the body to come to rest can be calculated as:

v = u + at

∴ t = -u / a = -15 / -2.5 = 6 s

Answer 2

Answer:

Refer to the Attachment.

Hope it Helps !!!!