Advertisements
Advertisements
Question
A stone is released from the top of a tower of height 19.6 m. Calculate its final velocity just before touching the ground.
Advertisements
Solution
Initial velocity, u = 0 m s-1
Final velocity, v =?
Height of the tower, h = 19.6 m
Acceleration due to gravity, g = 9.8 m s-2
Using the equation, v2 - u2 = 2gs = 2gh
v2 - 0 = 2 × 9.8 m s-2 × 19.6 m
v2 = 19.6 m s-2 × 19.6 m
v2 = (19.6)2 m2 s-2
or v = 19.6 m s-1
APPEARS IN
RELATED QUESTIONS
A stone is allowed to fall from the top of a tower 100 m high and at the same time another stone is projected vertically upwards from the ground with a velocity of 25 m/s. Calculate when and where the two stones will meet.
A ball thrown up vertically returns to the thrower after 6 s. Find
- the velocity with which it was thrown up,
- the maximum height it reaches, and
- its position after 4 s.
Give reason for the following :
The force of gravitation between two cricket balls is extremely small but that between a cricket ball and the earth is extremely large.
What is the force of gravity on a body of mass 150 kg lying on the surface of the earth? (Mass of earth = 6 x 1024 kg; Radius of earth = 6.4 x 106 m; G = 6.7 x 10-11 Nm2/kg2)
Name the force which stops you falling through the floor.
For freely falling object we can write the Newton’s second equation of motion as …..
Right or wrong sentence.
Free fall of an object does not depend on the mass of the object.
Write scientific reasons.
The value of gravitational acceleration (g) decreases as we go deep inside the earth.
Write scientific reasons.
The value of gravitational acceleration (g) is taken to be -g when studying the motion of an object thrown upwards in a straight line.
Distinguish between:
Universal gravitational constant – Gravitational acceleration of earth.
