Gravitation And UCM

Question 1

What is the difference between true weight and apparent weight?

Answer 1

True weight is the force of gravity exerted on you. Apparent weight is the normal force acting on you.

Question 2

When do you feel normal weight?

Answer 2

When stationary or moving at a constant speed.

Question 3

What happens to your apparent weight when you accelerate upward?

Answer 3

You feel heavier.

Question 4

What happens to your apparent weight when you accelerate downward?

Answer 4

You feel lighter.

Question 5

Calculate the acceleration of an elevator if a 40 kg person experiences a normal force of 425 N.

Answer 5

0.82 m/s² [up]

Question 6

What is Newton’s Law of Gravitation formula?

Answer 6

Fg = G * (m1 * m2) / r²

Question 7

What does G represent in Newton’s Law of Gravitation?

Answer 7

The gravitational constant (6.67 × 10⁻¹¹ Nm²/kg²)

Question 8

What does r represent in the gravitational formula?

Answer 8

The distance between the centers of two objects exerting gravity.

Question 9

What is the force of gravity on the James Webb Telescope if its mass is 6200 kg and it is 1.5 million km away?

Answer 9

1.1 N

Question 10

What is the relationship between force and distance in gravity?

Answer 10

It follows an inverse square law.

Question 11

If Satellite B has double the mass of Satellite A and orbits three times farther away, how does the force of gravity on Satellite B compare to Satellite A?

Answer 11

2.7 kN

Question 12

What is a gravitational field?

Answer 12

A field that exerts a force on any mass located in it.

Question 13

How do you calculate the gravitational field strength?

Answer 13

g = Fg / m0

Question 14

What is the gravitational field strength at Earth’s surface?

Answer 14

9.81 N/kg

Question 15

What is Uniform Circular Motion (UCM)?

Answer 15

Motion where velocity and force are perpendicular at all times.

Question 16

What is the formula for centripetal acceleration?

Answer 16

ac = v² / r

Question 17

What happens to the normal force (FN) at the bottom of a vertical loop?

Answer 17

It is larger than at the top.

Question 18

What are Kepler’s Laws of Planetary Motion?

Answer 18

1. Planetary orbits are ellipses with the sun at one focus. 2. A line connecting a planet to the sun sweeps out equal areas in equal times. 3. T²/r³ = constant for all planets.

Question 19

What is the formula to determine the mass of Earth using orbital data?

Answer 19

mE = (4π²r³) / (GT²)

Question 20

What is the formula to determine the orbital speed of a satellite?

Answer 20

v = √(G * mE / r)

Question 21

Fill in the blank: The gravitational force between two objects can be calculated using _______.

Answer 21

Newton’s Law of Gravitation

Question 22

True or False: An object feels its own gravitational field.

Answer 22

False