Science Enregy Review

Shawn will conduct a study of rolling a toy car down a ramp. Shawn plans to conduct a trial at four different heights. Then he will repeat all the trials after adding a weight to the toy car. He has prepared a table to record data from the study. The column headings of the table are listed below: * Trial * Height * Weight * Time Which statement correctly identifies an independent variable and a dependent variable of the study?

• Trial is an independent variable, and Weight is a dependent variable.

• Height is an independent variable, and Trial is a dependent variable.

• Time is an independent variable, and Height is a dependent variable.

• Weight is an independent variable, and Time is a dependent variable.

Mechanical energy is the sum of two types of energy—kinetic energy and potential energy of position. Which of the following is an example of an object that has kinetic energy?

• a snail crawling across a leaf

• a computer monitor sitting on a desk

• a tightly wound spring in a windup toy

• a roller coaster car just before it goes downhill

Raul wants to investigate how the angle of a ramp affects the speed of an object rolling down the ramp. He can conduct his investigation in a number of different ways. Which investigation should he perform?

• observe different bicyclists riding down hills of varying steepness

• record the time it takes one bicyclist to ride down hills of varying steepness

• perform an experiment in a lab in which the angle of the ramp is controlled and the speed of a rolling object is measured

• observe video of various objects rolling down hills and estimate the angle of the hill and the speed of the object

Tags

NGSS.MS-PS2-2

When a pendulum is released, it swings back and forth. The speed and position change throughout each swing. The illustration identifies three positions of a pendulum during its swing. At which point does the pendulum weight have the greatest amount of potential energy?

• Position 1

• Position 2

• Position 3

• Gravitational potential energy does not change.

Tags

NGSS.MS-PS3-2

A student lets a toy car roll four times down a ramp that is 1 m long. Each time the student covers the surface of the ramp with a different material. The student measures the time it takes the car to roll down the ramp and records the results in the table below.

• Different surfaces affect how fast a toy car accelerates.

• Different toy cars travel at different speeds.

• Gravity has little effect on the speed of toy cars on different surfaces.

• Air resistance is the greatest factor in limiting the acceleration of different toy cars.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-1

How does the law of conservation of energy apply to the changes in potential and kinetic energy of a pencil falling to the floor?

• Potential energy is converted into kinetic energy.

• Kinetic energy is converted into potential energy.

• Kinetic energy is created as potential energy is destroyed.

• Potential energy is created as kinetic energy is destroyed.

Tags

NGSS.MS-PS3-5

Brian rides his bike down a hill without needing to use the pedals. Which sentence best describes the change that is occurring?

• Kinetic energy is created from potential energy.

• Kinetic energy is being stored as potential energy.

• Potential energy is transformed into kinetic energy.

• Potential energy is being destroyed by kinetic energy.

Tags

NGSS.MS-PS3-5

Jerry tosses a ball into the air and watches it fall back to Earth. When does the ball only have potential energy?

• at its highest point

• as it leaves Jerry's hand

• just before it hits the ground

• halfway up to its highest point

Tags

NGSS.MS-PS3-2

The picture below shows a train as it approaches a hill. This train can only make it over the hill if it approaches at top speed because it will lose speed as it climbs. What changes are taking place in the train’s potential and kinetic energy as it climbs the hill?

• The train’s potential energy is increasing, and its kinetic energy is increasing.

• The train’s potential energy is increasing, and its kinetic energy is decreasing.

• The train’s potential energy is decreasing, and its kinetic energy is increasing.

• The train’s potential energy is decreasing, and its kinetic energy is decreasing.

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

One of Newton’s laws of motion states that objects in motion tend to stay in motion. What is a reason that this law may not always prove true for objects on Earth?

• The law is a mislabeled theory.

• Laws cannot be used to make predictions.

• The law is not supported by scientific observations or evidence.

• The conditions on Earth are different than the conditions specified in the law.