CLASS 9 SCIENCE MOTION QUESTION PAPER

MOTION

1. A horse accelerates steadily from rest at 4 m/s2 for 3s.
What is its final velocity and how far has it travelled?
(a) Initial velocity (u) = 0 Final velocity (v) = ?
Acceleration (a) = 4 m/s2 Time (t) = 3 s.
Known quantities u,a and t. Unknown v.
Correct equation is:   v = u + at
Final velocity (v) = 0 + 4x3 = 12 m/s
(b) Correct equation is s = ut + ½at2
Distance (s) = 0x3 + 0.5x4x9 = 18 m

2. A car travelling at 30 m/s accelerates steadily at 5 m/s2 for a distance of 70 m. What is the final velocity of the car?
Known quantities u,a and s. Unknown v.
Correct equation is v2 = u2 + 2as
Final velocity2 (v2) = 30x30 + 2x5x70
Therefore v = 40 m/s