Question

A car starts from rest and covers 15m in 5th second and 25m in 10th second determine inital velocity acceleration

Answer 1

The formula for displacement in the nth second is Sn=u+(2n-1)a/2

ATQ

S5=u+(2×5-1)a/2

15=u+9a/2

30=2u+9a-----(1)

S10=u+(2×10-1)a/2

25= u+19a/2

50=2u+19a-----(2)

Now subtract (2) from (1)

50=2u+19a

- 30=2u+9a

20=10a

a=2m/s²

substituting this value in eqn (1)

30=2u+9×2

2u = 30-18

u=12/2

u=6m/s