Science
A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. Find its acceleration. Find the force acting on it if it's mass is 7 tonnes.
(Hint: 1 tonne = 1000 kg)
Laws of Motion
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Answer
Given,
Distance (s) = 400 m
Time (t) = 20 sec
Initial velocity (u) = 0
According to the second equation of motion,
S = ut + at2
Substituting we get,
400 = 0 + x a x 20 x 20
a = = 2 ms-2
∴ acceleration of the car = 2 ms-2.
Now, mass = 7 tonnes
Converting tonne into kg
1 tonne = 1000 kg
∴ 7 tonnes = 7000 kg
Force = mass x acceleration
F = 7000 x 2 = 14000 N
Hence, Force acting = 14000 N
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