An object of mass 10 kg is placed on a plane inclined at an angle of 30 degrees
to the horizontal. The coefficient of kinetic friction between the object and the
plane is 0.12. The object is initially moving down the plane with a velocity of
4 metres per second. Calculate
(a) The acceleration of the block down the plane
(b) The distance the object moves down the plane in the first five seconds.
An object of mass 100 kilograms is initially at rest on the ground. A crane lifts
the object to a height of 15 metres in 8 seconds. When the object is 15 metres
above the ground, it is moving upwards with a velocity of 0.2m/s
Calculate
(a) The total mechanical energy of the object when it is 15 metres above the
ground.
(b) The average power of the crane.
A particle moves in a straight line with constant acceleration. Its displacement
from a fixed reference point O is 200 metres initially and 404 metres after 6
seconds. After 10 seconds it is 700 metres from O. Calculate
(a) its initial velocity
(b) its velocity after 20 seconds.
An object is thrown vertically upward with a speed of 20 metres per second
from the edge of a cliff which is 80 metres high. The object just misses the
edge of thecliff on the way down and falls to the bottom of the cliff. Calculate
(a) the total time the object takes to reach the bottom of the cliff
(b) the velocity of the object at the moment it just reaches the bottom
of the cliff.
