An object can exert a force on itself.

• True

• False

Tags

NGSS.MS-PS2-1

A basketball is bounced against the ground. How does the force exerted by the ball on the ground compare with the force exerted by the ground on the ball?

• The force exerted by the ball is greater.

• The forces exerted by the ball and the wall have the same magnitude.

• The force exerted by the ball is smaller.

• The relative magnitudes cannot be determined.

Tags

NGSS.MS-PS2-1

A person is riding in an elevator going down and increasing in speed. Which of the following is correct about the force F(P) that is exerted by the floor of the elevator on the person?

• F(P) is equal to the normal force, where F(P) is larger as the person moves down.

• F(P) is equal to the normal force, which decreases as the person moves down.

• F(P) is equal to the force of gravity, which does not change as the person moves down.

• F(P) is equal to the force of gravity, which decreases as the person moves down.

Tags

NGSS.HS-PS2-1

Action and reaction forces are always acting

• on the same object.

• on different objects.

• in the same direction.

• up.

Tags

NGSS.MS-PS2-1

Action and reaction forces are always acting

• on the same object.

• in opposite directions.

• in the same direction.

• up.

Action: When a swimmer pushes on water backward

• the water pushes the swimmer forward (reaction).

• the swimmer moves backward (reaction).

• the water moves backward (reaction).

• nothing happens.

Tags

NGSS.HS-PS2-1

Which statement is true about friction?

• Friction can act in the direction of motion.

• Friction always slows an object down.

• Friction is calculated using the coefficient of friction times the force of gravity.

• Friction cannot occur if an object is stationary.

Two masses, m1 and m2, are attached to each other by a string on a frictionless table. m1 is pulled to the right by an applied force (Fp). What is the correct equation for the motion of block m2? Ft is the tension of the string.

• Fp - Ft = m2 a

• Ft = m2 a

• Ft + Fp = m2 a

• Fp - Ft = (m1 + m2) a

Tags

NGSS.HS-PS2-1

Which statement best describes the acceleration of an atwood machine?

• It experiences constant acceleration.

• It experiences constantly changing acceleration.

• It experiences negative acceleration.

• It experiences increasing acceleration.

Tags

NGSS.HS-PS2-1

How can you determine the acceleration of an Atwood's Machine?

• m1 + m2

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4