CL-IX-PHYSICS Revision Day-4
Sl.
No Questions
.
1. In a rescue operation a food packet is dropped from a height of 500m. Find time
taken by it to reach the ground. Also calculate its velocity before reaching the
ground.
2. Two identical packets are dropped from two airplanes, one flying over the equator
and the other over the North Pole. Assuming all other conditions are identical, will
they take the same time to reach the ground? Justify your answer.
3. A ball thrown up vertically returns to the thrower after 8s. Find (a) the velocity with
which it was thrown up, (b) the maximum height it reaches, and (c) its position after
5seconds.
4. A stone is allowed to fall from the top of a tower 200 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.
5.
6. What happens to the force of gravitation between two objects if masses of
both the objects are doubled and distance between them is halved.
If the distance between the sun and the earth is increased to three times,
calculate the percentage change in the force of attraction between them.
7. A stone released from the top of a tower of height 180 m. calculate its final
velocity just before touching the ground.
How does the force of attraction between the two bodies depend upon their
masses and distance between them? A student thought that two bricks tied
together would fall faster than a single one under the action of gravity. Do
you agree with his hypothesis or not? Comment
8. Sahil was driving the car at a very high speed to reach the hospital and he tried to
Sl.
No Questions
.
1. In a rescue operation a food packet is dropped from a height of 500m. Find time
taken by it to reach the ground. Also calculate its velocity before reaching the
ground.
2. Two identical packets are dropped from two airplanes, one flying over the equator
and the other over the North Pole. Assuming all other conditions are identical, will
they take the same time to reach the ground? Justify your answer.
3. A ball thrown up vertically returns to the thrower after 8s. Find (a) the velocity with
which it was thrown up, (b) the maximum height it reaches, and (c) its position after
5seconds.
4. A stone is allowed to fall from the top of a tower 200 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.
5.
6. What happens to the force of gravitation between two objects if masses of
both the objects are doubled and distance between them is halved.
If the distance between the sun and the earth is increased to three times,
calculate the percentage change in the force of attraction between them.
7. A stone released from the top of a tower of height 180 m. calculate its final
velocity just before touching the ground.
How does the force of attraction between the two bodies depend upon their
masses and distance between them? A student thought that two bricks tied
together would fall faster than a single one under the action of gravity. Do
you agree with his hypothesis or not? Comment
8. Sahil was driving the car at a very high speed to reach the hospital and he tried to
