Gravitational Forces and Mass Calculations

The video tutorial covers solutions to problems 13 and 14 from a physics problem set on circular motion and gravity. Problem 13 involves calculating the mass of an electron using the gravitational force between two electrons. Problem 14 focuses on finding the ratio of gravitational forces exerted by the Sun and Earth on the Moon. The tutorial concludes with a reflective question about why the Moon orbits the Earth despite the Sun's stronger gravitational pull.

What is the gravitational force between two electrons 1 meter apart?

• 9.81 * 10^-31 Newtons

• 5.42 * 10^-71 Newtons

• 6.67 * 10^-11 Newtons

• 1.00 * 10^-10 Newtons

Which constant is used in Newton's universal law of gravitation?

• Gravitational constant

• Boltzmann's constant

• Planck's constant

• Coulomb's constant

What is the calculated mass of an electron in Problem 13?

• 9.01 * 10^-31 kg

• 1.67 * 10^-27 kg

• 5.97 * 10^24 kg

• 7.35 * 10^22 kg

Why might the calculated mass of an electron differ from the reference value?

• Due to measurement errors

• Due to wrong units

• Due to significant figures

• Due to incorrect formula

What is the mass of the Sun used in Problem 14?

• 7.35 * 10^22 kg

• 5.98 * 10^24 kg

• 1.99 * 10^20 kg

• 2 * 10^30 kg

What is the distance between the Moon and the Sun in Problem 14?

• 3.84 * 10^8 m

• 1.50 * 10^11 m

• 6.67 * 10^-11 m

• 9.81 * 10^2 m

What is the gravitational force between the Sun and the Moon?

• 4.36 * 10^20 Newtons

• 9.81 * 10^2 Newtons

• 1.99 * 10^20 Newtons

• 6.67 * 10^-11 Newtons

What is the gravitational force between the Earth and the Moon?

• 9.81 * 10^2 Newtons

• 4.36 * 10^20 Newtons

• 6.67 * 10^-11 Newtons

• 1.99 * 10^20 Newtons

What is the ratio of the gravitational force exerted by the Sun on the Moon to that by the Earth on the Moon?

• 3.84

• 2.19

• 1.99

• 4.36

Why doesn't the Moon revolve around the Sun despite the Sun's stronger gravitational pull?

• The Moon's orbit is fixed

• The Earth's gravitational pull is stronger

• The Moon is closer to the Earth

• The Sun's gravitational pull is weaker