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Class 11
Physics
Laws of Motion
a constant force acting on a body of mass 3 0 kg c...

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?

Answer:

0.18 N; in the direction of motion of the body

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, the acceleration (a) produced in the body can be calculated as:

v= u + at

∴ a = v-u / t

= (3.5 - 2) / 25 = 1.5 / 25 = 0.06 m/s²

As per Newton's second law of motion, force is given as:

F= ma

= 3 × 0.06 = 0.18 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.

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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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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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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?