) Is work a vector or scalar? Define “energy”. A wooden sphere of mass 0.15 kg is thrown
with a velocity of 30 ms-1 .Find the kinetic energy of the sphere. (4-marks )
(b) Define “work” . Write down the unit of work in SI system. A woman push a child, who is
riding a tricycle, with a 200N force. The tricycle moves a distance of 2m and the work done
by the woman is 100J. Find the angle between the force and the displacement. (4-marks )
- (a) Define speed and velocity such that the two may be distinguished. An object moves with
an initial velocity of 4ms-1 . If it moves with a uniform acceleration of 2ms-2 find the
displacement after 20 s. (4-marks )
(b) A body moving with a constant acceleration reach the velocity 4ms-1 after 10s. If the
body start from rest , find the velocity after (a) 12s (b) 14s (c) 16s (d) 18s. Draw the
velocity time graph for the interval 10 s to 18 s. From the graph , find the velocities at
8s and 20s. (4marks )