Understanding Gravity and Universal Gravitation

The video explores the concept of gravity, starting with the approximation of 9.81 m/s² near Earth's surface. It delves into Newton's law of universal gravitation, explaining how gravity is calculated using the gravitational constant, Earth's mass, and radius. The video highlights discrepancies in gravity measurements due to Earth's non-uniform density and shape. It further examines how gravity changes at higher altitudes, such as where the International Space Station orbits, and clarifies misconceptions about gravity in orbit.

What is the approximate value of acceleration due to gravity near the Earth's surface?

• 8.91 meters per second squared

• 9.81 meters per second squared

• 10.81 meters per second squared

• 11.81 meters per second squared

According to Newton's law of universal gravitation, what is the force of gravity between two objects proportional to?

• The sum of the masses of the objects

• The difference in the masses of the objects

• The square of the distance between the objects

• The product of the masses of the objects

When calculating acceleration due to gravity, which mass cancels out in the formula?

• Mass of the Earth

• Mass of the object

• Gravitational constant

• Radius of the Earth

What is the calculated value of acceleration due to gravity at the Earth's surface using the universal law of gravitation?

• 10.02 meters per second squared

• 9.82 meters per second squared

• 9.92 meters per second squared

• 9.72 meters per second squared

What is the gravitational constant used in the calculations?

• 6.6738 x 10^-13

• 6.6738 x 10^-12

• 6.6738 x 10^-11

• 6.6738 x 10^-10

What is the radius of the Earth used in the calculations?

• 5,371 kilometers

• 6,371 kilometers

• 7,371 kilometers

• 8,371 kilometers

Why is there a discrepancy between the calculated and textbook values of gravity?

• Earth is not a perfect sphere and has non-uniform density

• Earth has uniform density

• Earth is a perfect sphere

• Earth's radius is constant everywhere

What is the acceleration due to gravity at an altitude of 400 kilometers?

• 10.69 meters per second squared

• 9.69 meters per second squared

• 8.69 meters per second squared

• 7.69 meters per second squared

What remains constant when calculating gravity at higher altitudes?

• Gravitational constant and mass of the Earth

• Distance from the Earth's center

• Mass of the object

• Radius of the Earth

Why does it feel like there is no gravity in orbit?

• There is no gravitational force in space

• The space station is in free fall, moving fast enough to miss Earth

• The space station is moving too slowly

• The space station is too far from Earth