### All High School Physics Resources

## Example Questions

### Example Question #1 : Universal Gravitation

Two satellites in space, each with a mass of , are apart from each other. What is the force of gravity between them?

**Possible Answers:**

**Correct answer:**

To solve this problem, use Newton's law of universal gravitation:

We are given the constant, as well as the satellite masses and distance (radius). Using these values we can solve for the force.

### Example Question #1 : Understanding Universal Gravitation

Two satellites in space, each with a mass of , are apart from each other. What is the force of gravity between them?

**Possible Answers:**

**Correct answer:**

To solve this problem, use Newton's law of universal gravitation:

We are given the constant, as well as the satellite masses and distance (radius). Using these values we can solve for the force.

### Example Question #1 : Understanding Universal Gravitation

Two satellites in space, each with equal mass, are apart from each other. If the force of gravity between them is , what is the mass of each satellite?

**Possible Answers:**

**Correct answer:**

To solve this problem, use Newton's law of universal gravitation:

We are given the value of the force, the distance (radius), and the gravitational constant. We are also told that the masses of the two satellites are equal. Since the masses are equal, we can reduce the numerator of the law of gravitation to a single variable.

Now we can use our give values to solve for the mass.

### Example Question #7 : Universal Gravitation

Two asteroids in space are in close proximity to each other. Each has a mass of . If they are apart, what is the gravitational force between them?

**Possible Answers:**

**Correct answer:**

To solve this problem, use Newton's law of universal gravitation:

We are given the constant, as well as the asteroid masses and distance (radius). Using these values we can solve for the force.

### Example Question #2 : Universal Gravitation

Two asteroids in space are in close proximity to each other. Each has a mass of . If they are apart, what is the gravitational acceleration that they experience?

**Possible Answers:**

**Correct answer:**

Given that , we already know the mass, but we need to find the force in order to solve for the acceleration.

To solve this problem, use Newton's law of universal gravitation:

We are given the constant, as well as the satellite masses and distance (radius). Using these values we can solve for the force.

Now we have values for both the mass and the force, allowing us to solve for the acceleration.

### Example Question #51 : Forces

Two asteroids, one with a mass of and the other with mass , are apart. What is the gravitational force on the LARGER asteroid?

**Possible Answers:**

**Correct answer:**

To solve this problem, use Newton's law of universal gravitation:

We are given the constant, as well as the asteroid masses and distance (radius). Using these values we can solve for the force.

It actually doesn't matter which asteroid we're looking at; the gravitational force will be the same. This makes sense because Newton's 3rd law states that the force one asteroid exerts on the other is equal in magnitude, but opposite in direction, to the force the other asteroid exerts on it.

### Example Question #1 : Understanding Universal Gravitation

Two asteroids, one with a mass of and the other with mass are apart. What is the gravitational force on the SMALLER asteroid?

**Possible Answers:**

**Correct answer:**

To solve this problem, use Newton's law of universal gravitation:

We are given the constant, as well as the asteroid masses and distance (radius). Using these values we can solve for the force.

It actually doesn't matter which asteroid we're looking at; the gravitational force will be the same. This makes sense because Newton's 3rd law states that the force one asteroid exerts on the other is equal in magnitude, but opposite in direction, to the force the other asteroid exerts on it.

### Example Question #1 : Understanding Universal Gravitation

Two asteroids, one with a mass of and the other with mass are apart. What is the acceleration of the SMALLER asteroid?

**Possible Answers:**

**Correct answer:**

Given that Newton's second law is , we can find the acceleration by first determining the force.

To find the gravitational force, use Newton's law of universal gravitation:

We now have values for both the mass and the force. Using the original equation, we can now solve for the acceleration.

### Example Question #2 : Understanding Universal Gravitation

Two asteroids, one with a mass of and the other with mass are apart. What is the acceleration of the LARGER asteroid?

**Possible Answers:**

**Correct answer:**

Given that Newton's second law is , we can find the acceleration by first determining the force.

To find the gravitational force, use Newton's law of universal gravitation:

We now have values for both the mass and the force. Using the original equation, we can now solve for the acceleration.

### Example Question #11 : Universal Gravitation

Two satellites are a distance from each other in space. If one of the satellites has a mass of and the other has a mass of , which one will have the smaller acceleration?

**Possible Answers:**

Neither will have an acceleration

They will both have the same acceleration

We need to know the value of the masses to solve

**Correct answer:**

The formula for force and acceleration is Newton's 2nd law: . We know the mass, but first we need to find the force:

For this equation, use the law of universal gravitation:

We know from the first equation that a force is a mass times an acceleration. That means we can rearrange the equation for universal gravitation to look a bit more like that first equation:

can turn into: and , respectively.

We know that the forces will be equal, so set these two equations equal to each other:

The problem tells us that

Let's say that to simplify.

As you can see, the acceleration for is twice the acceleration for . Therefore the mass will have the smaller acceleration.