Problems on acceleration due to gravity and variation of acceleration due to gravity, class 11

Problems on acceleration due to gravity and variation of acceleration due to gravity, class 11 | Physics Advocate

Q1.

Calculate the percentage decrease in the weight of a body when it is taken to a height of 40 km above the Earth's surface. Radius of Earth = 6,400 km

Ans. 1.25%

Q2.

Calculate the depth below the surface of Earth where the acceleration due to gravity is 25% of its value at the Earth's surface. Take, radius of Earth = 6,400 km.

Ans. 4.8 × 10⁶ m

Q3.

A body weighs 100N on Earth's surface. Calculate the gravitational force on the body at a height equal to one-fourth the radius of Earth.

Ans. 64 N

Q4.

Calculate the percentage decrease in weight of a body when taken to a tunnel 38.4 km below the Earth's surface.

Ans. 0.6%

Q5.

Calculate the height from the Earth's surface at which the acceleration due to gravity becomes 75% compared at Earth's surface. Take, radius of Earth = 6,400 km.

Ans. 990 km

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EXTRA QUESTIONS

Q6.

Find the percentage increase in acceleration due to gravity on the surface of a planet if its radius shrinks by 0.5% and its mass remains constant.

Ans. 1%

Q7.

If the whole Earth was made of iron of relative density 7.86, what would be the value of acceleration due to gravity on its surface?

Ans. 14.04 m/s²

Q8.

Keeping the mass constant, if radius of Earth increases by a factor 3, then by which factor density must have to be changed so that the value of 'g' remains the same?

Ans. 1/3

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Variation of g with height (video class)

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