Unit 3 & Univ. Grav. Test Review Projectile Motion

Projectile Motion

By Maria Cerca

​Unit 3: Test Review

Horizontal time is the same as vertical time.
Which angle will allow an object to travel the farthest?

Projectile Motion

​Acceleration (m/s²)
Force (N)
Velocity (m/s)

Centripetal

Universal Gravitation

​Directly Proportional:
Force and mass

​Inversely Proportional:
Force and distance

Multiple Choice

In any projectile motion problem, which variable is constant?

• horizontal distance

• horizontal time

• acceleration

• vertical distance

Multiple Choice

If you throw a baseball straight up, what is its velocity at the highest point?

• 9.8 m/s²

• 0 m/s²

• 9.8 m/s

• 0 m/s

Multiple Choice

A ball rolls off a table that is 4m high and hits a target 8m away. What is the initial horizontal velocity?

• 8.9 m/s

• 5.0 m/s

• 10.0 m/s

• 7.5 m/s

Multiple Choice

An athlete throws a football off the stands onto a football field, 20m below, at a speed of 8m/s. Using equations for projectile motion, describe how far away the football lands from the athlete.

• 16.2 m.

• 10.5 m.

• 18.3 m.

• 22.7 m.

Multiple Choice

A swimmer runs off a pool’s diving board at 5m/s and lands in the water 10 meters away from the edge of the diving board. Calculate how high above the swimming pool the diving board is located.

• 19.6 m

• 15.6 m

• 10.7 m

• 5.0 m

Multiple Choice

What is the centripetal acceleration required to keep a 2000 kg car moving in a circular path of radius 25.0 meters with a velocity of 10 m/s?

• 4 m/s²

• 5 m/s²

• 3 m/s²

• 0.4 m/s²

Multiple Choice

At the instant shown in the image, in which direction is the car's velocity?

• Toward E

• Toward W

• Toward N

• Toward S

Multiple Choice

At the instant shown in the image, in which direction is the car's centripetal force?

• Toward E

• Toward W

• Toward N

• Toward S

Multiple Choice

A rock tied to a string is traveling at a constant speed of 4 m/s in a circle of a radius 1.5 m. Calculate the magnitude of the centripetal acceleration of the rock. What is the direction of the acceleration?

• 10.7 m/s²

• 8.0 m/s²

• 12.5 m/s²

• 2.7 m/s²

Multiple Choice

A rock tied to the end of a string moves in a circle at a constant speed of 2.5 m/s and experiences an acceleration of 4.0 m/s². What is the radius of the circle of its motion?

• 1.6 m

• 2.0 m

• 1.2 m

• 25 m

Multiple Choice

The force vector should be drawn ___, the velocity vector should be drawn ___ of the circular path.

• towards the center,

  tangent

• tangent, towards the center

• outwards, tangent

• tangent, outwards

Draw

Draw the force, velocity and, acceleration vectors and make sure that you label each. Use a different color for each vector.

Multiple Choice

Two factors effecting the magnitude of the force of gravity between 2 objects are...

• mass and distance 
• mass and matter
• distance and weight 
• weight and mass

Multiple Choice

If I double the mass of one object, but don't change anything else... What happens to the gravitational force between two objects?

• Doubles
• Quadruples
• Cut in Half
• 4x Smaller

Multiple Choice

Which of the following will not change in different gravitational fields?

• wieght
• force
• mass
• pounds

Multiple Choice

Which of the following will change with different gravitational forces?

• mass
• amount of matter in an object
• weight
• kilograms

Multiple Choice

The gravitational force between the two spheres is 40N.

Scenario: The distance between the two masses is then halved. What will the magnitude of the new force be when this happens.

• 20 N

• 40 N

• 80 N

• 160 N

Multiple Choice

Force of gravity is directly proportional to

• Mass
• Weight
• Distance
• Time

Multiple Choice

Complete the following statement: The farther away two planets are the _______ the gravitational force between them.

• more
• same
• dosen't matter
• less

Multiple Choice

Two asteroids exert a gravitational force, F, on each other. Some time later, the asteroids are now three times as far from each other as before. Which of the following represents the gravitational force at this distance? 

• F/3
• F/2
• F/6
• F/9

Multiple Choice

Find the distance between two objects whose masses are m₁ = 4,500 kg, and m₂ = 8,700 kg; if the gravitational force between them is F = 2.0 x 10^-8 N.

• 130565.25 m

• 361.3 m

• 0.1958 m

• 0.783 m

Multiple Choice

Calculate the force of attraction between Jupiter and Saturn. Jupiter has a mass of 1.898 x 10²⁷ kg and Saturn has a mass of 5.683 x 10²⁶ kg. The approximate distance between them is 7.786 x 10¹¹ m.

• 1.187 x 10²⁰ N

• 9.876 x 10¹⁹ N

• 2.345 x 10²⁰ N

• 3.786 x 10²⁰ N

Multiple Choice

Mercury is the closest planet to the sun and has a mass of 3.30 x 10²⁴ kg. The sun has a mass of 1.99 x 10³⁰ kg. Mercury is 5.79 x 10¹⁰ m away from the sun. What is the gravitation force between them?

• 1.31 x 10²² N

• 2.59 x 10³³ N

• 4.12 x 10²⁷ N

• 3.37 x 10²⁵ N

Multiple Choice

A satellite with a mass of 200 kg is orbiting a planet at a distance of 500,000 meters, and the gravitational force is 0.1 N. Determine the mass of the second planet.

• $$1.0 \times 10^{24}$$ kg

• $$1.5 \times 10^{24}$$ kg

• $$2.0 \times 10^{24}$$ kg

• $$2.5 \times 10^{24}$$ kg

Fill in the Blanks

Convert 135 cm to meters. Include the unit in your response.