Question

an object accelerates uniformly along a straight line from a velocity of 10ms-1 until 25ms-1 in 5s.
a)the velocity of the object during the first 10s of motion
b)the time taken to reach a final velocity 50ms-1

Answer 1

V = 10 + 3 t

Answer 2

Initial velocity U=10m/s
Final velocity V=25m/s
Velocity V= 25m/s-10m/s=15m/s
Time t=5s
(a) In 5s, the velocity v= 15m/s.
In 10s, the velocity
v= 15m/s×2=30m/s.
(b) V=50m/s a=dv/t=15m/s÷5s=3m/s^2
V=u+at
50m/s=10m/s+(3m/s^2×t)
50m/s=10+3t
50-10=3t
40=3t
t=40/3=13.666
Thus, t=13.67s.