Cuestionario de Física

Josie is the quarterback of her football team, the Bulldogs. Which of the following options best describes what happens to the ball right after Josie throws a pass?

• Kinetic energy is transferred from the ball to the air.

• Kinetic energy is transferred from Josie's arm to the ball.

• Potential energy is transferred from the ball to the air.

• Potential energy is transferred from Josie's arm to the ball.

The graph below shows the relationship between the mass of an object and its gravitational potential energy. What can be concluded from the graph?

• The gravitational potential energy decreases with mass.

• The gravitational potential energy increases with mass.

• There is no relationship between mass and gravitational potential energy.

Three students analyze the image below of a child sledding down a snow-covered hill. The students make separate statements about the image: Student 1 claims: The child/sled has the greatest potential energy at the lowest point of the hill while the sled is still accelerating. Student 2 claims: The child/sled has the greatest kinetic energy at the lowest point of the hill while the sled is still accelerating. Student 3 claims: The child/sled has equal amounts of potential and kinetic energy halfway down the hill. Which student, if any, is correct?

• Student 2, since potential energy is transformed into kinetic energy as the child/sled accelerates down the hill.

• Student 1, since kinetic energy is transformed into potential energy as the child/sled accelerates down the hill.

• Student 3, since potential energy and kinetic energy balance out when the child/sled reaches the midpoint of the hill.

A 500-kilogram wrecking ball swings from a crane towards a brick wall. At the top of its swing, the wrecking ball is momentarily stationary (not moving). What is its kinetic energy?

• 0 J

• 500 J

• 1000 J

• 2000 J

During a softball game, the pitcher throws the ball and the batter hits it. The batter hits a home run and the ball hits the fence at the end of the field. Which of the following energy transformations occur during the event? Choose the 3 that apply.

• 0 J

• 500 J

• 250 J

• 1000 J

Johanna took her little brother to the park because he likes to swing. Which statement is true about the transformation between kinetic and potential energy while the child is swinging?

• Kinetic energy is maximum at the highest point of the swing.

• Potential energy is maximum at the lowest point of the swing.

• Kinetic energy is maximum at the lowest point of the swing.

• Potential energy is constant throughout the movement.

The difference between a physical change and a chemical change is that a chemical change creates a new substance. For example, when water freezes, it undergoes a physical change but does not transform into a different substance. Choose the three elements that describe physical changes.

Potential energy is converted into kinetic energy between points A and B.

• True

• False

Potential energy is converted into kinetic energy between points B and C.

• True

• False

Potential and kinetic energy remain constant between points A and C.

• True

• False