8th Grade Science Review

Which statement best explains the backward motion of the boat as the person moves forward?

• Every mass exerts a force on every other mass

• Friction opposes the motion of an object

• For every action there is an equal but opposite reaction

Tags

NGSS.MS-PS2-1

According to Newton's Second Law of Motion, acceleration of an object depends on the mass of the object and the...

• net weight of the object

• gravity of the object

• trajectory of the object

• net force acting on the object

Tags

NGSS.HS-PS2-1

A push or pull that always acts on an object is called?

• speed

• motion

• acceleration

• force

Tags

NGSS.MS-PS2-1

An object is resting motionless on a surface. According to Newton's First Law, the object will only start to move if...

• the net forces on the object equal zero

• an unbalanced force is applied to the object

• the upward force of the object is equal to its acceleration

• two forces that are equal and opposite are applied to the object

Tags

NGSS.MS-PS2-2

Which statement best describes the differences between speed and velocity?

• speed is the distance divided by time; velocity is total distance

• speed is how fact an object is moving; velocity includes speed and direction

• velocity is how fast an object is moving

Friction occurs because of...

• the roughness of any object's surface

• only the weights of any two objects

• only the masses of any two objects

• unbalanced forces

Tags

NGSS.MS-PS2-2

When a person pushes on a wall, why doesn't the wall fall over?

• the wall cannot exert a force on anything

• the wall is pushing back with same force

• the wall is pulling on a person

• the person pushing on the wall can't get enough friction

Tags

NGSS.MS-PS2-1

What is the purpose of using a parachute when skydiving?

• to create an upward force of air resistance and slow down

• to reduce the friction force and speed up

• to go faster than terminal velocity

• to balance out the forces and stop the skydiver from moving

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-5

Which of the following best describes friction?

• a force that works against gravity

• a form of energy that depends on light and heat

• a force that opposes motion between two surfaces that are touching

• a force that controls gravity

Tags

NGSS.3-PS2-1

NGSS.3-PS2-2

What can cause a moving object to increase its speed in a forward direction?

• a force pushing on the object from the opposite direction

• a force that continually acts on the object in the direction the object is moving

• an increase in the mass of the object

• a decrease in the force on the object

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2