Question

An object of mass 100 kg is accelerated uniformly from a velocity of 5 ms-1 to 8 ms-1 in 6 s. Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on the object.

  • force and laws of motion CBSE Class 9
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Answer

Initial velocity of the object, u = 5 m/s

Final velocity of the object, v = 8 m/s

Mass of the object, m = 100 kg

Time take by the object to accelerate, t = 6 s

Initial momentum = mu = 100 × 5 = 500 kg ms-1

Final momentum = mv= 100 × 8 = 800 kg ms -1

Force exerted on the object, 𝐹 = {𝑚𝑣−𝑚𝑢 \over 𝑡}

f formula

Initial momentum of the object is 500 kg ms-1 .

Final momentum of the object is 800 kg ms -1 .

Force exerted on the object is 50 N.

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