Forces

Roger and William are performing an experiment testing which type of surface allows a toy car to travel down a ramp the fastest. They tested four different materials and gathered results. Which of the following forces applied to the cars is a contact force

• Gravity

• Magnetism

• Friction

• Electricty

Looking at the figure above, which of the blocks above will have the greatest acceleration to the right

• Block 1

• Block 2

• Block 3

• Block 4

Brody brings a magnet near an object. He notices that the object is pulled closer to the magnet. He can flip the magnet to the other side and notices the object is pushed away by the same force. Which of the following best describes the magnetic force

• A contact force

• A gravitational force

• A force that acts from a distance

• A frictional force

What is the primary force responsible for the motion of the water over a waterfall, and how does this force affect the water

• the force of air pressure because it pushes the water downward

• the force of friction because it applies a downward pulling force on the water along the rough rocks

• the force of magnetism, because it pushes the water downward

• the force of gravity because it applies a pulling force on the water along the sloping land

Maricela and Joaquim are standing very close to each other. They are not touching. Which of the following statements is true about the forces that are present

• there is a small gravitational repulsion between the two students

• there is a large magnetic attraction between the two students

• the only gravitational attraction occurs between the two students and Earth

• there is a small gravitational attraction between the two students

Which is a factor that affects the strength of gravitational, magnetic, and electric forces

• mass

• volume

• distance

• density

Four cars are traveling down the highway at 70 mph. Some of the characteristics of the cars are listed in the table. Which car does Earth'gravity exert the greatest force against?

• Car a

• Car b

• Car c

• Car d

How would the gravitational force between the Earth and the Moon change if the mass of Earth doubled but its diameter stayed the same

• the amount of gravitational force by the Earth on the Moon would increase pulling the moon closer

• the amount of gravitational force by the Earth on the Moon would decrease pushing the moon away

• the amount of gravitational force by the Earth on the Moon would stay the same, so the orbit would stay the same

• the amount of gravitational force by the Earth on the Moon would disappear causing the moon to leave the solar system

The gravitational pull between objects is greater when the objects

• have greater mass

• have rougher surfaces

• are farther apart

• are moving at greater speed

If an object is moving at a constant speed in one direction, what is needed to change its speed or direction

• a long period of time

• an unbalanced force

• a balanced force

• a short period of time