Energy

Shawn will conduct a study of rolling a toy car down a ramp. Shawn plans to conduct a trial at four different ramp heights. Then he will repeat all the trials after adding a weight to

the toy car. He has prepared a table to record the 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

Tags

NGSS.MS-PS3-1

Raul wants to investigate how the angle of a ramp affects the speed 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 cart 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. This 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.

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. Which of these would be the best conclusion based on the data in the table?

• 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

Two students are rolling marbles down a ramp and measuring how long they take to reach the bottom. They each have a bag containing marbles made of different materials that are also different sizes and colors. What can the students do to be sure their results can be reproduced?

• Make sure that they both use the same color marbles.

• Make sure that they test the marbles at different times.

• Be sure to use marbles of the same size and material each time.

• Be sure they guess how long the marbles will take to go down the ramp.

How does the law of conservation of energy apply to the changes in potential and kinetic energy of a pencil as it falls 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 potential energy is destroyed.

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-5

Brian rides his bike down a hill without needing to use the pedals. Which sentence best describes the change in energy 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 following graph shows the results of an experiment done by four different groups. Each group took a different rubber band and recorded how far it stretched as they added weights to it. Which group’s rubber band stretched the least as more weight was added?

• group 1

• group 2

• group 3

• group 4