Advertisements
Advertisements
प्रश्न
Write scientific reasons.
When we drop a feather and a stone at the same time from a height the stone reach the earth faster than a feather.
Advertisements
उत्तर
- When we drop a feather and a heavy stone at the same time from a height, the feather experiences a buoyant force and a frictional force due to air and therefore floats and reaches the ground slowly.
- But the buoyant and frictional forces on the stone are much less than the weight of the stone and does not affect the speed of the stone much.
- Hence, when we drop a feather and a stone at the same time from a height, the stone reach the earth faster than a feather.
APPEARS IN
संबंधित प्रश्न
A stone is released from the top of a tower of height 19.6 m. Calculate its final velocity just before touching the ground.
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.
When an object is dropped from a height, it accelerates and falls down. Name the force which accelerates the object.
Explain why, the tip of a sewing needle is sharp.
A pressure of 10 Pa acts on an area of 3.0 m2. What is the force acting on the area ? What force will be exerted by the application of same pressure if the area is made one-third ?
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
Solve the problem.
If the mass of a planet is eight times the mass of the Earth and its radius is twice the radius of the Earth, what will be the escape velocity for that planet?
i) If g = GM/r2 then where will the value of g be high at Goa Beach or on top of Mount Everest?
The value of acceleration due to gravity of earth :
The acceleration produced in a body by a force of given magnitude depends on
A force of 10 N acts on a body of mass 5 kg. Find the acceleration produced.
Define the term acceleration due to gravity? Write its S.I. unit.
How are g and G realated ?
What force, in newton, your muscles need to apply to hold a mass of 5 kg in your hand? State the assumption.
What do you understand by the free fall?
Right or wrong sentence:
The value of gravitational acceleration at the centre of earth is zero.
Define acceleration due to gravity.
Write a short note.
Free Fall
