Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

Normal Size Small Size show me how

Normal Size Small Size show me how

# Chapter 3

### DHS PS Ch. 3 - Forces (Online Course)

Question | Answer |
---|---|

What happens to the gravitational force as objects get farther apart? | It decreases rapidly but never gets to zero |

You exert a gravitational force on _________. | everything |

How does weight relate to mass? | Weight is mass times acceleration due to gravity. |

What causes thrown objects to travel in a curved path? | Earth's gravitational pull and the inertia of the object |

What happens to the amount of gravity a projectile experiences as it moves through the air? | It remains constant |

What provides centripetal force when a car experiences centripetal acceleration around a corner? | friction between the tires and road |

In which direction is the centripital force? | toward the center of the circle |

Astronauts "float" when inside an orbiting spaceship because they are _______________ | in free fall. |

Newton's third law of motion states that ____________. | for every action force there is an equal and opposite reaction force that occurs at the same exact time. |

What causes a rocket to move ? | The rocket's engines exert a force on exhaust gases and the gases exert a force back on the rocket. |

If two objects with different masses and traveling with different velocities collide, what law allows you to predict the motion of the objects after the collision? | the law of conservation of momentum |

Whenever a force is exerted, another force occurs that is ______ in size, and ________ in direction. | equal, opposite |

Action-reaction force pairs never __________? | act on the same object. |

An object will have zero momentum if ________. | it has zero velocity or zero mass |

What is the reaction force when you place a cup on a table? | the force of the table back up on the cup |

When a falling object reaches terminal velocity, the force of gravity ___________ the force of air resistance. | is equal and opposite to. |

When force is increased on an object, what happens to its acceleration? | It increases. |

When gravitational forces and air resistance equalize on an object that is falling toward Earth and the object stops accelerating, what is the velocity of an object called? | terminal velocity |

Name 3 benefits to friction. | It allows objects to start, stop, or turn. |

All objects fall at a constant rate of 9.8 m/s2 unless you factor in _________ | air resistance. |

Which of the following will result in the greatest acceleration? | The greatest force acting on the smallest mass. |

Newton's second law of motion is ____________? | an object will accelerate in the direction of an applied force, depending on the object's mass. |

Static friction occurs when two objects are _______________. | at rest |

The upward force on an object falling through the air is _______________. | air resistance |

The relationship among mass, force, and acceleration is explained by ________________. | Newton's second law of motion |

A feather will fall through the air more slowly than a brick because of _____________. | air resistance |

In a vacuum, an apple and a feather that are dropped from the same height at the same time will ___________________. | fall at the same rate |

The acceleration due to gravity near the Earth's surface is always _____________. | 9.8 m/s2 |

According to Newton's second law of motion, ______________________. | F = ma |

The path of a projectile is _______________. | always curved |

For any object, the greater the force that's applied to it, the greater its __________ will be. | acceleration |

The size of the gravitational force between two objects depends on their _________________. | masses and the distance between them |

As you get farther from the surface of Earth, your weight will _________________. | decrease |

When a force is exerted on a box, an equal and opposite force is exerted by the box. These forces are called ____________________. | action-reaction |

A real car moving at 10km/h has more momentum than a toy car moving at the same speed because the real car _________________. | has greater mass |

In the equation p = m x v, the p represents ___________________. | momentum |

The statement "to every action there is an equal and opposite reaction" is _____________. | Newton's third law of motion |

Momentum is measured in what units? | kg x m/s |

When two objects collide, the momentum of the balls after the collision is explained by ______________________. | the law of conservation of momentum |

An object that is in free fall seems to be ____________________. | weightless |

If gravity did NOT affect the path of a horizontally thrown ball, the ball would _________________________. | continue to travel horizontally |

The motion of an object parallel to Earth's surface is _______________________. | horizontal |

If a 500-N action force is exerted to the right, the reaction force will be ________________________. | 500 N to the left |

Friction between the tire of a moving car and the dry pavement is ____________ friction. | rolling |

Gravity is one of ____________ basic forces. | four |

What exerts the strongest gravitational force on you? | Earth |

What happens immediately after a sky diver opens her parachute? | Air resistance greatly increases. |

Which object has the greatest inertia between a bowling ball, tennis ball, and a beach ball? | a bowling ball (it has the most mass) |

If a greater force is applied to Car A compared to Car B, Car A will have _______________ acceleration as (than) Car B. | greater |

How does weight relate to mass? | Weight is mass times acceleration due to gravity. |

Force and motion are ______________________. | connected |

When a force is applied to an object, the _________ of an object will affect acceleration. | mass |

Newton's second law of motion states that acceleration is equal to force _____________ by mass. | divided |

If two surfaces are touching each other, what force opposes the motion between them? | friction |

What is the ultimate source of friction where surface bumpers stick together? | microwelds |

Which type of friction occurs between two surfaces that are not moving past each other? | static |

The force that opposes the motion of two surfaces sliding past each other is called _____________ friction. | sliding |

When a force occurs between a rolling object and the surface it rolls on, it is known as ____________________ friction. | rolling |

What opposes the motion of objects that move through the air? | air resistance |

An object's size, shape, and speed depend on the _____________ of air resistance. | amount |

Is gravity a ______ _______ force that gives the universe its structure? | long-range |

The four basic forces include electromagnetic force, strong nuclear force, weak nuclear force, and ___________________. | gravity |

Regardless of mass, all objects fall with the same acceleration due to __________________. | inertia |

What is the gravitational force exerted on an object called? | weight |

If weight results from a force, then _________ is a measure of how much matter an object contains. | mass |

What do objects in the space shuttle do when they have no force supporting them? | float |

When an object accelerates toward the center of a curved path _____________ acceleration occurs which is caused by centripital ____________. | centripital, force |

Newton's third law of motion states that to every action force there is an equal and ___________________ reaction force. | opposite |

Rocket propulsion is based on ______________? | Newton's third law of motion |

Action-reaction forces differ from balanced forced as they act on different or identical objects? | different |

What is related to how much force is needed to change an object's motion? | momentum |

The law of conservation of momentum states that momentum can be __________________ between objects; momentum is not lost or gained in the transfer. | transferred |

Two objects have the same mass. Object A is motionless. Object B is traveling at 2 m/s. After they collide, the stick together and move as one unit. What is their resultant velocity? | 1 m/s since the mass is doubled (the velocity is now half) |

Which law explains why a motorcycle will always beat a car if they both produce the same amount of force? | Newton's 2nd law |

Which law explains why once a satellite is put in motion, it will continue to stay in motion? | Newton's 1st law |

Which law explains why when a canon fires a canon ball, the canon ball goes one direction while the canon goes the opposite? | Newton's 3rd law |

Which law allows you to predict the motion of objects after a collision? | Law of conservation of momentum |

Where did Isaac Newton attend college? | Cambridge University in Britain |

Why did Newton's college close down for 18 months in 1665? | Because of the bubonic plague |

You can only add forces together when they are _________ ? | in the same direction |

You must subtract forces when they are __________ ? | in opposite directions. |

If two object are twice as far apart, the gravitational force between them is now _____ as strong. | half |

If two object are 3x as far apart, the gravitational force between them is now _____ as strong. | 1/9th |

If two object are 4x as far apart, the gravitational force between them is now _____ as strong. | 1/16th |

If two object are 10x as far apart, the gravitational force between them is now _____ as strong. | 1/100th |

Weight is measure in _______ . | Newtons |

Gravitational strength is measure in _______ . | N/kg |

The gravitational force on the moon is ______ as strong as the Earth's. | 1/6th |

Newton's first law of motion is also known as the law of _____ . | inertia |

These work in a car crash to keep a passenger from being thrown out as well as decreasing the amount of force experienced. | Seat belts |

Air bags inflate using a chemical reaction that produces _______ . | nitrogen gas |

Created by:
basmith