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प्रश्न
Write a short note.
Escape Velocity
उत्तर
- The minimum velocity with which a body should be projected from the surface of a planet or moon, so that it escapes from the gravitational influence of the planet or moon is called as escape velocity.
- Escape velocity is given as, `"v"_"esc" = sqrt((2"GM")/"R") = sqrt(2"gR")`, where M is mass of the planet, R is radius of the planet and g is acceleration due to gravity of the planet.
- The escape velocity is different for different planets.
संबंधित प्रश्न
A ball is thrown vertically upwards with a velocity of 49 m/s. Calculate
- the maximum height to which it rises.
- the total time it takes to return to the surface of the earth.
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.
What is the acceleration produced in a freely falling body of mass 10 kg ? (Neglect air resistance)
What force is responsible for the earth revolving round the sun ?
State whether the following statement is true or false :
A falling stone also attracts the earth.
Fill in the following blank with suitable word :
The acceleration due to gravity on the moon is about ………………of that on the earth.
During a free fall, will heavier objects accelerate more than lighter ones ?
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.
Name the force which stops you falling through the floor.
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 of 15 N acts on a body of mass 2 kg. Calculate the acceleration produced.
A force acts for 10 s on a stationary body of mass 100 kg, after which the force ceases to act. The body moves through a distance of 100 m in the next 5 s. Calculate : The acceleration produced by the force
A body falls freely under gravity from rest and reaches the ground in time t. Write the expression for the height fallen by the body.
What is the acceleration due to gravity?
What do you understand by the free fall?
The value of gravitational acceleration at the centre of earth is zero.
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.
The mass of planet ‘X” is four times that of the earth and its radius is double the radius of the earth. The escape velocity of a body from the earth is 11.2 × 103 m/s. Find the escape velocity of a body from the planet 'X’.
