Pre-U Gravitational Fields

The Earth may be assumed to be spherical with radius r and density ⍴.

Which equation correctly relates the gravitational field strength g at its surface to these quantities and the gravitational constant G?

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Tags

NGSS.HS-PS2-4

The gravitational field strength outside a uniform sphere of mass M is the same as that of a point mass M at the centre of the sphere. The Earth, which may be assumed to be spherical and of radius r, has a gravitational field strength g at its surface.

Which expression gives the gravitational field strength at height h above the ground?

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Tags

NGSS.HS-PS2-4

Two isolated masses m₁ and m₂ are separated by a distance r.

Which expression gives the gravitational field strength caused by m₁ at m₂?

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Tags

NGSS.HS-PS2-4

What is numerically equal to the gravitational field strength at a point P on the Earth's surface?

• the acceleration of free fall at P

• the change in potential energy per unit distance from P

• the force acting on any body placed at P

• the work done in bringing unit mass from infinity to P

Tags

NGSS.HS-PS2-4

Which statement about a uniform gravitational field is true?

• Its magnitude is the same in all directions

• The gravitational potential has the same value at all points within it

• Its direction is opposite to the direction of motion of a test mass released in it

• Its field strength is the same at all points within it

A body of mass 20 kg mass is placed 4 m above the Earth's surface. The value of g may be taken as 10 ms^-2.

What are the gravitational field strength and gravitational force acting on the body?

• A

• B

• C

• D

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

The acceleration of free fall on the Earth's surface may be taken to be 6 times the value on the Moon's surface. The mean density of the Earth may be taken to be 5/3 times the value of the Moon. The radius of the Earth is r_E and that of the moon is r_M.

What is the ratio r_E / r_M

• 1.9

• 3.6

• 6.0

• 10

Tags

NGSS.HS-PS2-4

A mass m is released just above the surface of a planet with mass M and radius R.

Which expression gives its initial gravitational acceleration?

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Tags

NGSS.HS-PS2-4

The Earth may be assumed to be spherical with mass M and radius R, with acceleration of free fall g at its surface. Which equation correctly shows how the universal gravitational constant G is related to these quantities?

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Tags

NGSS.HS-PS2-4

The given diagram illustrates how the acceleration of free fall is determined by timing the fall of a steel ball photo-electrically. After release from P, the ball passes X and Y at time t_x and t_y.

Which expression gives the acceleration of free fall?

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Tags

NGSS.HS-PS2-1