B3 PHYSICS Exam Unit 3

A 1 kg cart moving at 4 m/s collides inelastically with a 2 kg mass which is initially at rest. Which of the following statements is not true about the momentum of the two carts?

• The two carts have the same velocity after the collision

• The total kinetic energy of the system is the same before and after the collision

• Before the collision, the total momentum was equal to the momentum of the 1 kg cart

• After the collision, the 2 kg cart has more momentum than the 1 kg cart

Tags

NGSS.HS-PS2-2

A railroad flatcar of mass rolls to the right with a momentum of 20,000 kg*m/s and collides with another flatcar that is rolling to the left with a momentum of -15,000 kg*m/s. What is the total momentum of the two flatcar system after they collide?

• 5,000 kg*m/s

• 10,000 kg*m/s

• 20,000 kg*m/s

• 35,000 kg*m/s

Tags

NGSS.HS-PS2-2

Which cart has less mass?

• Cart A because it changed its velocity less

• Cart B because it changed its velocity less

• Cart A because it changed its velocity more

• Cart B because it changed its velocity more

Tags

NGSS.HS-PS2-1

A 1 kg rock is dropped off a 90 m high cliff. After falling 20 m, the kinetic energy of the rock-Earth system is approximately -

• 20 J

• 200 J

• 700 J

• 900 J

Tags

NGSS.HS-PS3-1

A 0.6 kg spring with a spring constant of 1200 N/m is compressed 5.0 cm from its equilibrium position by a mass. How much energy is stored in the spring-mass system? (Hint! You need to convert cm to meters!)

• 1.5 J

• 3.0 J

• 3,000 J

• 15,000 J

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

Two physics students conduct a recoil experiment. The two carts above start at rest. If the final momentum of cart B is -2.4 kg*m/s and momentum was conserved in the recoil, what is the final momentum of cart A?

• -2.4 kg*m/s

• 0 kg*m/s

• 2.4 kg*m/s

• It is not possible to determine with the information provided

Tags

NGSS.HS-PS2-2

While testing his archery skills, Robin Hood shoots an arrow at an apple which is at rest. The 0.2 kg arrow has a velocity of 40 m/s and sticks to the apple as they collide. If the final velocities of the arrow and apple are both 10 m/s, what is the mass of the apple?

• 0.2 kg

• 0.4 kg

• 0.6 kg

• 0.8 kg

Tags

NGSS.HS-PS2-2

A rocket, like the one in the diagram below, operates by using engines to shoot exhaust gases down towards the ground. What is true about the forces acting on the rocket?

• The force of gravity on the rocket must be equal to the force of the exhaust gasses on the rocket

• The force of the exhaust gases on the rocket will be equal to the force of the rocket on the exhaust gases, but in the opposite directions

• The force of the exhaust gases on the rocket must be greater than the force of the rocket on the exhaust gases

• The force of gravity on the rocket must be greater than the force of the exhaust gasses on the rocket

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

What type of energy is in the bird-Earth system of a bird that is sitting on a powerline?

• Kinetic Energy

• Gravitational Potential Energy

• Elastic Potential Energy

• Kinetic AND Gravitational Potential

Tags

NGSS.MS-PS3-2

What is the correct SI unit for mass?

• Kilograms
• newtons
• pounds
• grams

Tags

CCSS.3.MD.A.2