Energy Comparison of a Skater

Compare the amount of potential energy and kinetic energy of the skater at each position. Explain your findings.

Answer explanation

At the highest point, potential energy is maximum and kinetic energy is minimum. As the skater descends, potential energy decreases while kinetic energy increases, showing energy conversion between the two forms.

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

Which chart will match your answer from question 1?

Answer explanation

The chart that corresponds to your answer from question 1 should visually represent the same data or trends discussed, ensuring clarity and alignment with the provided information.

Tags

NGSS.MS-PS3-2

Which statements accurately describe the potential and kinetic energy of the bicyclist?

• Kinetic energy increases and Potential energy decreases

• Kinetic energy increases and Potential energy remains constant

• Kinetic energy remains constant and Potential energy decreases

• Kinetic energy remains constant and Potential energy increases

Answer explanation

As the bicyclist accelerates downhill, kinetic energy increases due to higher speed, while potential energy decreases as they descend. Thus, the correct statement is that kinetic energy increases and potential energy decreases.

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

Rollercoasters are popular attractions at amusement parks. A cart on a roller coaster approaches the highest point on the coaster. Which statement best describes the roller coaster as it slows down while traveling to the top of the coaster?

• The cart gains both kinetic and potential energy.

• The cart gains kinetic energy and loses potential energy.

• The cart loses kinetic energy and gains potential energy.

• The cart loses both kinetic and potential energy.

Answer explanation

As the cart climbs to the highest point, it slows down, losing kinetic energy due to decreased speed. Simultaneously, it gains potential energy because it is moving to a higher elevation, making the correct choice: the cart loses kinetic energy and gains potential energy.

Tags

NGSS.MS-PS3-5

Which action represents a conversion of chemical energy into mechanical energy?

• Pancakes reheated in a microwave oven.

• Soup beginning to boil on a stove.

• A grasshopper jumping from a predator

• Sunlight melting an icicle

Answer explanation

A grasshopper jumping from a predator converts stored chemical energy from its muscles into mechanical energy for movement, making it the correct choice. The other options involve thermal or solar energy, not chemical to mechanical.

Ocean tides result mainly from

• Surface winds.

• Radiant heat from the Sun.

• Earth’s tilt on its axis.

• The moon's gravitational pull.

Answer explanation

Ocean tides are primarily caused by the moon's gravitational pull, which creates bulges in the Earth's oceans. This gravitational interaction is the main factor influencing the rise and fall of sea levels, making it the correct answer.

Tags

NGSS.MS-PS2-4

In astronomy class, students are looking at various alignments of the Sun, the Moon, and Earth. Which effect does the right-angle alignment shown have on Earth?

• There will be a solar eclipse on Earth.

• A full moon will be observed from Earth.

• The high tides will be lower than normal on Earth.

• An increased gravitational force will be extended on Earth.

Answer explanation

The right-angle alignment of the Sun, Moon, and Earth results in lower gravitational pull from the Moon, leading to lower high tides on Earth. This is known as neap tide, which occurs when the gravitational forces are minimized.

Tags

NGSS.MS-ESS1-1

The net force on a vehicle that is accelerating at a rate of 1.5 m/s² is 1,800 newtons. What is the mass of the vehicle to the nearest kilogram?

(a)  

Answer explanation

To find the mass, use Newton's second law: F = m * a. Rearranging gives m = F / a. Here, m = 1800 N / 1.5 m/s² = 1200 kg. Thus, the mass of the vehicle is 1200 kg.

Tags

NGSS.MS-PS2-2

Which diagram shows the relative position of Earth’s axis at the beginning of summer in Texas.

• A

• B

• C

• D

Answer explanation

Choice C correctly illustrates Earth's axis tilted towards the Sun, indicating the beginning of summer in Texas, where longer daylight and warmer temperatures occur.

Tags

NGSS.MS-ESS1-1

The model shows Earth in four different positions in its orbit around the sun. Which statement correctly explains which position of Earth represents summer in the United States?

• Position 1, because the Western Hemisphere is facing the sun.

• Position 2, because the Northern Hemisphere tilts toward the sun.

• Position 3, because Earth is at its closest point to the sun in its orbit.

• Position 4, because Earth is traveling at its fastest rate in its orbit.

Answer explanation

Position 2 correctly represents summer in the United States because the Northern Hemisphere is tilted toward the sun, receiving more direct sunlight and longer days during this time.

Tags

NGSS.MS-ESS1-1