Question

20. For a body starting from rest, the distance travelled
(d) is directly proportional to the square of the time
elapsed from the start (t). When t= 4 sec, d = 48 m. What
is the value of d (in metres) at t = 7 sec?
(A) 128 (B) 150 (C) 115 (D) 147​

Answer 1

Answer:

the value is 128 option a

Answer 2

Answer: 147 m

Step-by-step explanation: From given question,

(d) is directly proportional to the square of the time  elapsed from the start (t)

d ∝ ( t )²

For t= 4 sec, d = 48 m.

d = k ( t )²

48 = k ( 16 )²

 k = 3

Now, find d =? when t = 7 sec

d = k ( t )²

d = 3 * ( 7 )²

d =  147 m