Question

65. Ram starts his bike from rest and moves along a
straight path. If he attains a speed of 72 km h-1 in
10 s, determine his acceleration.​

Answer 1

Answer:

Explanation:

Given,

Initial velocity of bike, u = 0 m/s (As starts from rest)

Final velocity of bike, v = 72 km/h = 72 × 5/18 = 20 m/s

Time taken by bike, t = 10 seconds

To Find,

Acceleration by bike, a

Formula to be used,

1st law of motion,

v = u + at

Solution,

Putting all the values, we get

v = u + at

⇒ 20 = 0 + a × 10

⇒ 20 = 10a

⇒ 20/10 = a

⇒ a = 2 m/s²

Hence, the acceleration is 2 m/s².

Answer 2

Given :-

Ram starts his bike from rest and moves along a  straight path. If he attains a speed of 72 km h-1 in  10 s,

To Find :-

Acceleration

Solution :-

We know that

1 km/h = 5/18 m/s

72 km/h = 72 × 5/18 = 4 × 5 = 20 m/s

Now

a = v - u/t

a = 20 - 0/10

a = 20/10

a = 2/1

a = 2

Hence

Acceleration is 2 m/s²

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