Question

A particle moving in a straight line experience constant acceleration for 20s after starting from rest. If it travels a distance S1 in the first 10s and distance S2 in the next 10s,then find relation between S1 and S2.​

Answer 1

Given :

▪ Initial velocity = zero (i.e., rest)

▪ Distance covered in first 10s = S¹

▪ Distance covered in last 10s = S²

▪ Total time of journey = 20s

To Find :

▪ Relation b/w S¹ and S².

SoluTion :

Since, acceleration has said to be constant throughout the motion, we can easily apply second equation of kinematics to solve this question.

↗ S = ut + 1/2(at²)

✴ Distance covered in first 10s :

→ S¹ = (0×10) + 1/2(a×10²)

→ S¹ = 0 + 1/2(100a)

→ S¹ = 50a .......... (i)

✴ Total distance covered in 20s :

→ S = (0×20) + 1/2(a×20²)

→ S = 0 + 1/2(400a)

→ S = 200a

✴ Distance covered in last 10s :

→ S = S¹ + S²

→ 200a = 50a + S²

→ S² = 150a .......... (ii)

✴ Taking ratio of (i) and (ii), we get

→ S¹/S² = 50a/150a

→ S¹/S² = 1/3

→ S¹ : S² = 1 : 3