Physics Form 4 Part 2

The acceleration of gravity on the Moon is almost 6 times less than on earth. If the weight of the astronaut on Earth is 850 N, what is his mass on the Moon

[Gravitational field strength of Earth = 9.81 m s^-2]

• 14.17 kg

• 85.00 kg

• 86.65 kg

• 141.67 kg

Which statement is TRUE to explain Newton’s Universal Law of Gravitation?

• Gravitational force is a gravitational constant

• The force of gravity increase linearly to the product of the mass of two bodies

• Gravitational force can be an attractive force or a repulsive force

• The force of gravity is inversely proportional to the square of the distance between the centers of the two bodies

The gravitational attraction between the two bodies increases when their ...

• masses are reduced and distance reduced

• masses are increased and distance reduced

• masses are reduced and distance is increased

• masses are increases and distance is increased

Two protons of mass 1.67 x 10^-27 kg separated by 1.4 x 10^-14 m.

Calculate the attraction force between the protons.

• 6.67 x 10^-23

• 7.96 x 10^-24

• 9.49 x 10^-37

• 1.42 x 10^-48

What is the gravitational force of the sun on a 15.0 kg box on the Earth's surface when the Sun's mass is 2.0 x 10³⁰ kg and the distance between Earth and Sun 1.5 x 10¹¹ m?

• 8.9 x 10^-2 N

• 4.5 x 10^-1 N

• 9.2 x 10² N

• 4.0 x 10⁵ N

The weight an object on the surface on the Earth is 100 N.

What is the attraction force between the object and the Earth?

• 0 N

• 10 N

• 100 N

• 1 000 N

A man made satellite orbits the Earth at a distance of 1.45 × 10⁴ km from Earth’s center. The moon orbits the Earth at a distance of 3.84 × 10⁵ km once every 27.3 days.

How long does it take the satellite to orbit the Earth?

• 0.20 days

• 3.07 days

• 243 days

• 3721 days

What is the force required to keep a 10 kg model train moving in a circle of radius 5 m when the train has a linear speed of 0.4 m s^-1?

• 0.08 N

• 0.80 N

• 0.20 N

• 0.32 N

The frictional force between the wheels and the surface of the road is 1000 N , when the car moves in a roundabout with a linear speed 15 km h^-1.

What is the linear speed of the car when the frictional force between the wheels and the surface of the road is 4000 N.

• 8 km h^-1

• 15 km h^-1

• 30 km h^-1

• 60 km h^-1

The diagram shows a merry-go-round at a playground with a radius of 5 m. The linear speed of the merry-go-round is 4 m s^-1.

What is the centripetal acceleration of the merry-go-round?

• 3.20 m s^-2

• 1.25 m s^-2

• 0.80 m s^-2

• 0.16 m s^-2