Question

The velocity of the body moving in a straight line with a constant accelaration, is 10m/sec at a certain instant 't'. After 5sec the velocity become 20m/sec, the velocity 3sec before 't' was:
A). 4m/s
B). 6m/s
C). 7m/s

Answer 1

u = 10 m/s
v = 20 m/s
time = 5s

a = $\frac{v-u}{t} = \frac{20-10}{5} =2$ m/s²

3 second before t,
t= -3
velocity = 10 + 2(-3) = 10-6 = 4m/s

Answer 2

4m/s (Option A)..........