[T3] ETA Reviewer

Sir Fred pushes the pile of papers on his desk to make way for the ETA papers. What BEST defines WORK in this context?

• The energy transferred by pushing the papers over a distance.

• The force applied by Sir Fred to an object without causing movement.

• The potential energy stored in the ETA papers while at rest on the desk.

• The velocity of the papers being displaced.

CJ is pushing a box above her head. Work is related to energy because: (Click all correct answers.)

• Energy enables CJ to do work.

• Work done on the box is equal to CJ's change in energy.

• Energy and work can be solved by multiplying mass, gravitational acceleration, and height (displacement).

• Energy and work can have N⋅m as its unit.

Identify situations in which work is done and in which no work is done.

Groups:

(a) There is WORK done.

,

(b) There is NO WORK done.

• Sir Ez doing push-ups.

• Ms. Nes opening the door to her classroom.

• Ms. Chay pushing an immovable wall for class demonstration.

Elijah is carrying a bag and is moving horizontally across the school field. Is there work done?

• Yes, because he is moving.

• No, because the bag is being displaced parallel to the field.

• Yes, because he is exerting force to carry his bag.

• No, because the force and displacement of the bag are not parallel.

Ezra is using a treadmill at the gym to do his daily workout. He will try to finish his routine today in half the time he normally would. What can we infer given this scenario?

• Ezra will not notice any change since it is his normal routine.

• Ezra will get tired quickly because he will use more power to finish his workout fast.

• Ezra will use more power because he will exert less work in his new routine.

• Ezra will use less power because he will finish in less amount of time.

Keisha is holding a ball at the top of a hill. Which of the following best describes the ball's energy as it rolls down the hill?

• PE will change as KE changes, but their sum always stays the same.

• PE will increase as it started to roll.

• KE is at the maximum at the top of the hill.

• PE and KE will always be equal according to Law of Conservation of Energy.

The Kinetic Energy is directly proportional to the square of the body's ​ (a)   while its Potential Energy is directly proportional to its ​ (b)   .

• position
• speed
• contact time
• impulse

At which points does the skater's total mechanical energy have the same values?

• A and B

• B and C

• B and D

• A and C

Sofie is reviewing for her upcoming exam and needs to practice solving. Which of the following involves solving gravitational potential energy problems?

• Calculating the energy stored in a compressed spring

• Finding the energy required to lift an object to a certain height

• Determining the velocity of a car at the bottom of a hill

• Finding the energy required to increase the temperature of an object by 1°C.

Ram is training for his off-season basketball game. If he passes a 0.60-kg ball at a velocity of 10. m/s, what is the kinetic energy of the ball?

• 3.0 Joules

• 6.0 Joules

• 30. Joules

• 60. Joules