Question

2. A body moves from rest with a uniform
acceleration and travels 250m in 5sec. Find the
velocity of the body at 8 second after the start.
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Answer 1

Answer:400 m/s

Explanation:accleration per sec=250/5=50

speed after 8 secs=50*8=400

Answer 2

Given:-

• Initial velocity ,u = 0m/s

• Distance travelled ,s = 250 s

• Time taken ,t = 5 s

To Find:-

• Velocity of body at 8 second after start , v .

Solution:-

Firstly we calculate the acceleration of the body. Using 2nd Equation of Motion

• s = ut+1/2at²

v is the final velocity

a is the acceleration

u is the initial velocity

t is the time taken

s is the distance covered

Substitute the value we get

→ 250 = 5×0 +1/2×a×5²

→ 250 = 0 + 1/2×a×25

→ 250 ×2 = a×25

→ 500 = a×25

→ a = 500/25

→ a = 20m/s²

Acceleration of body is 20m/s².

Now , calculating the final velocity of body at 8 second after start . Using 1st equation of motion

• v = u+at

Substitute the value we get

→ v = 0 + 20×8

→ v = 160m/s

Therefore, the final velocity of the body at 8 second after start is 160 m/s.