Question

3. A motor boat starting from rest on a lake accelerates in a straight line at a constant
rate of 3m/s? for 8 seconds. How far the boat does travel during this time? (3)​

Answer 1

AnswEr :

Given that motor boat starting from rest accelerates uniformly at a constant rate of 3 m/s² for 8 seconds.

We have to find distance travelled by motor boat during this time.

From the given data :

Initial speed (u) = 0 [As it starts from rest]

Acceleration (a) = 3 m/s²

Time (t) = 8 seconds.

From the 2nd equation of motion i.e. s = ut + ½ at²,

Substituting values,

→ s = 0 × 8 + ½ × 3 × 8²

→ s = 0 + ½ × 3 × 64

→ s = 0 + 32 × 3

→ s = 0 + 96

→ s = 96 m

∴ Distance travelled by motor boat during that time = 96 m [Answer]

Answer 2

Given that

Initial velocity of motorboat, u = 0

Acceleration of motorboat, a=3.0ms-2

Time under consideration, or time taken t = 8.0s

Formula

We know the equation of motion

Distance, s = ut + (1/2)at2 —————-(i)

Substituting the given and known values in equation (i) we get,

s= 0 (8) + 1/2 (3) (8)2

= 1/2 (3) (64) { 82 = 8 X 8=64}

= 3(32)

= 96

Therefore, The distance travel by motorboat = 96 m

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