FOR 2024. ALL EXAM REVISION QUESTIONS AND CORRECT
ANSWERS (ALREADY GRADED A+) (2024 UPDATE)
Which best explains what happens to the motion of the pendulum? - ANSWER- A.
The mechanical energy transforms to thermal energy as the pendulum slows and eventually stops
moving.
A battery has chemical energy, which can be used to generate thermal and radiant energy in a
lightbulb. Which best explains what happens to the amount of energy in this scenario? - ANSWER-
C.
The total energy in the system remains the same as the decrease in chemical energy equals the
increase in thermal and radiant energy.
Which activity directly converts energy from the Sun into chemical energy? - ANSWER- C.
a bean plant making its own food to grow
Alana summarized what happens when a ball sitting on top of a grassy hill rolls down the hill.
The motionless ball has potential energy. Once the ball starts to roll down the hill, new kinetic
energy is made. As the ball rolls across the grass, it slows down. The kinetic energy of the ball is
converted to other forms of energy.
Which best describes Alana's error? - ANSWER- B.
Kinetic energy is not made; it is a result of energy transformation.
,Energy can be transformed from one form to another. The diagram shows one such process.
Which energy transformation is represented in the diagram? - ANSWER- A.
nuclear to thermal and radiant
Almost all energy on Earth comes from the ____. - ANSWER- Sun
Which best explains how to correct Savion's error? - ANSWER- B.
Reorder the steps so that step 4 appears before step 3.
Eddie stated the picture shows potential energy being transformed to kinetic energy. Val stated that
it shows chemical energy being transformed to mechanical energy. Which best explains who is
correct? - ANSWER- c.
Both Eddie and Val are correct because chemical energy is a type of potential energy and
mechanical energy includes kinetic energy.
Which energy transformation does the picture best illustrate? - ANSWER- A.
radiant to chemical
Solar-powered cars use energy from the Sun to work. A panel on the car absorbs light energy from
the Sun, which then generates an electric current. This electric current, in turn, allows the car to
move. Which shows the correct order of energy transformations that take place in a solar-powered
car? - ANSWER- D.
radiant, electrical, mechanical
,Pablo prepares to lift a barbell. During which stage of the lift does Pablo do work on the barbell?
- ANSWER- NOT B.
when he applies force to the barbell but has not moved it
Henry can lift a 200 N load 20 m up a ladder in 40 s. Ricardo can lift twice the load up one-half
the distance in the same amount of time.
Which comparison between Ricardo and Henry is correct? - ANSWER- NOT B.
Ricardo exerted a greater force, did the same amount of work, and had a greater power output than
Henry.
Adita lifts a book from the floor, carries it across the room, and places it on a high shelf. When is
Adita doing work on the book? - ANSWER- D.
She does work as she picks up the book and as she lifts it to the shelf.
A force acts on an object and moves it a certain distance. The product of the force and the distance
is the _____ done on the object - ANSWER- WORK
Which lists the students in order from the greatest amount of work done to the least? (Work: W =
Fd) - ANSWER- NOT C.
Bill, Chet, Mika, Sara
When work is measured in joules and time is measured in seconds, power is measured in _____. -
ANSWER- WATTS
, A lawnmower engine running for 20 min does 4,560,000 J of work. What is the power output of
the engine? (Power: P = W/t) - ANSWER- NOT B.
228,000 W
When force is measured in newtons and distance is measured in meters, the work done is measured
in - ANSWER- joules
During which step does the robotic arm do work on the block? - ANSWER- B.
Step 2
Den pushes a desk 400 cm across the floor. He exerts a force of 10 N for 8 s to move the desk.
What is his power output? (Power: P = W/t) - ANSWER- B.
5W
Jill applies a force of 250 N to a machine. The machine applies a force of 25 N to an object. What
is the mechanical advantage of the machine? - ANSWER- A.
0.1
Lucy needs to lift a crate to a shelf 20 m high. She does 12,000 J of work on a machine to help her.
The machine exerts a force of 500 N to lift the crate.
What is the efficiency of the machine? - ANSWER- NOT B.
24%
Which statement best describes why a machine is useful? - ANSWER- NOT C.