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A body at rest is acted upon by a force for 20 seconds. The force is then withdrawn and the body moves a distance of 60m in the next 5 secon
Question
A body at rest is acted upon by a force for 20 seconds. The force is then withdrawn and the body moves a distance of 60m in the next 5 seconds. If the mass of the body is 10 kg, calculate the magnitude of the force.
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Physics
3 years
2021-08-30T15:52:30+00:00
2021-08-30T15:52:30+00:00 2 Answers
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Answers ( )
Answer:
6 N
Explanation:
Given:
v₀ = 0 m/s
v = 60 m / 5 s = 12 m/s
t = 20 s
Find: a
a = Δv / Δt
a = (12 m/s − 0 m/s) / 20 s
a = 0.6 m/s²
F = ma
F = (10 kg) (0.6 m/s²)
F = 6 N
Answer:
6N
Explanation:
From the principle of conservation of momentum.
The momentum initiated by the Force F in 20sec is the impulse and is given as;
F×t= F×20 = 20F
Similarly the mass 10kg acquires a momentum of m×v; where m is mass =10kg and v is the velocity of the body.
The velocity of the body, V = Distance/ time =60/5=12m/s
Hence the momentum is;
10×12= 120Ns
By conservation of momentum;
20F =120
F = 120/20 = 6N