Newton's Second Law (Quiz)

How much force is needed to accelerate an object of mass 90 kg at a rate of 1.2 m/s2?

C. 108 N

A box that has a mass of 80 kg slides down a ramp with a 30 degree angle. The free-body diagram shows the forces acting on the box.

Ignoring friction and air resistance, what is the acceleration of the box, to the nearest tenth?

B. 4.9 m/s2

A rocket experiences a constant force even as the amount of fuel in its fuel tanks decreases. What happens to the acceleration of the rocket as it runs out of fuel?

D. The acceleration increases because the mass decreases

Tracy stands on a skateboard and tosses her backpack to her friend who is standing in front of her. Which best describes the acceleration Tracy experiences?

A. It is less than the acceleration of the backpack because she has a greater mass.

wrong B. It is greater than the acceleration of the backpack because she has a greater mass.

C. It is less than the acceleration of the backpack because she uses a smaller force.

D. It is greater than the acceleration of the backpack because she uses a larger force.

The weight of a bucket is 186 N. The bucket is being raised by two ropes. The free-body diagram shows the forces acting on the bucket.

The acceleration of the bucket, to the nearest tenth, is m/s2.

wrong 5.0

What is the mass of an object if a net force of 8.0 N causes it to accelerate at 1.1 m/s2?

B. 7.3 kg

The gravitational acceleration on Earth is 9.8 m/s2. What is the weight of a car on Earth (to the nearest whole number) if it has a mass of 1360 kg?

D. 13,328 N

An object pulled to the right by two forces has an acceleration of 2.5 m/s2. The free-body diagram shows the forces acting on the object.

What is the weight of the object?

D. 490 N

Chang sees the following formula on a website about Newton's second law.

a =

What does the symbol F in the formula indicate that Chang needs to do?

A. He needs to find the net force acting on the object in a direction.

B. He needs to use only forces acting in the direction of motion.

wrong C. He needs to combine the horizontal and vertical forces.

D. He needs to multiply the horizontal and vertical forces.

Devon has several toy car bodies and motors. The motors have the same mass, but they provide different amounts of force, as shown in this table.

The bodies have the masses shown in this table.

Which motor and body should Devon use to build the car with the greatest acceleration?

C. motor 2, with body 1

Which quantity may be calculated directly using Newton's second law of motion?

A. weight

wrong B. velocity

wrong C. position

D. direction

A sled that has a mass of 8 kg is pulled at a 50 degree angle with a force of 20 N. The force of friction acting on the sled is 2.4 N. The free-body diagram shows the forces acting on the sled.

What is the acceleration of the sled and the normal force acting on it, to the nearest tenth?

A. a = 1.3 m/s2; FN = 63.1 N

B. a = 1.6 m/s2; FN = 65.6 N

wrong C. a = 1.9 m/s2; FN = 93.7 N

wrong D. a = 2.2 m/s2; FN = 78.4 N

What is the mass of a crate if a net force of 12 N gives the crate an acceleration of 0.20 m/s2?

wrong A. 2.4 kg

B. 6 kg

wrong C. 12.2 kg

D. 60 kg

For problems that involve an object accelerating along an inclined plane, how can the weight be used to determine the force component that causes motion?

A. The weight is the full force that acts perpendicular to the surface of the ramp.

wrong B. The weight times the cosine of the ramp's angle is the force perpendicular to the ramp.

C. The weight times the sine of the angle of the ramp acts down along the ramp.

wrong D. The weight times the cosine of the angle of the ramp acts down along the ramp.

Which formula is used to calculate the mass of an object if the force and acceleration are known?

A. m = Fa

B. m = F/A

wrong C. m = A/F

wrong D. m = F - a