Advertisements
Advertisements
Question
Write a short note.
Free Fall
Solution
- The motion of any object under the influence of the force of gravity alone is called free fall.
- In free fall, the initial velocity of the object is zero and goes on increasing due to the acceleration due to gravity of the earth.
- During free fall, the frictional force due to air opposes the motion of the object and a buoyant force also acts on the object.
- Thus, true free fall is possible only in a vacuum.
APPEARS IN
RELATED QUESTIONS
What do you mean by acceleration due to gravity?
A stone is thrown vertically upward with an initial velocity of 40 m/s. Taking g = 10 m/s2, find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone?
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.
When an object is dropped from a height, it accelerates and falls down. Name the force which accelerates the object.
During a free fall, will heavier objects accelerate more than lighter ones ?
The values of g at six distances A, B, C, D, E and F from the surface of the earth are found to be 3.08 m/s2, 9.23 m/s2, 0.57 m/s2, 7.34 m/s2, 0.30 m/s2 and 1.49 m/s2, respectively.
(a) Arrange these values of g according to the increasing distances from the surface of the earth (keeping the value of g nearest to the surface of the earth first)
(b) If the value of distance F be 10000 km from the surface of the earth, state whether this distance is deep . inside the earth or high up in the sky. Give reason for your answer.
Why does a sharp knife cut objects more effectively than a blunt knife ?
Name the force which wears away two surfaces as they move over one another.
Name the force which stops you falling through the floor.
An object thrown vertically upwards reaches a height of 500 m. What was its initial velocity? How long will the object take to come back to the earth? Assume g = 10 m/s2
i) If g = GM/r2 then where will the value of g be high at Goa Beach or on top of Mount Everest?
Choose one or more correct alternatives.
Which of the forces involved in dragging a heavy object on a smooth, horizontal surface, have the same magnitude?
- The horizontal applied force
- gravitational force
- reaction force in vertical direction
- force of friction
A force acts for 0.1 s on a body of mass 2.0 kg initially at rest. The force is then withdrawn and the body moves with a velocity of 2 m s-1. Find the magnitude of the force.
How is the acccelaration due to gravity on the surface of the earth realted to its mass and radius ?
An object falling freely from rest reaches ground in 2 s. If acceleration due to gravity is 9.8 m s-2, then the velocity of object on reaching the ground will be
What force, in newton, your muscles need to apply to hold a mass of 5 kg in your hand? State the assumption.
Write scientific reason.
The value of gravitational acceleration (g) decreases as we go deep inside the earth.
Write scientific reason.
The value of gravitational acceleration (g) is taken to be -g when studying the motion of an object thrown upwards in a straight line.
