Praxis Middle School Science

A child pulling a wagon along a sidewalk suddenly notices the wagon is slowing down. If the child continues to pull on the wagon with a forward force of 12 N, which of the following best describes the force of friction on the wagon as it slows?

• greater than 12 N

• equal to 12 N

• 
  less than 12 N

Answer explanation

The force of friction will slow the wagon if the friction force is greater than the forward force. Since the wagon is slowing, the friction force must be greater than the 12 N force of the pull.

Tags

NGSS.MS-PS2-2

Which of Newton's laws describes the force that keeps Mars in orbit around the Sun?

• Newton's first law of motion

• Newton's second law of motion

• Newton's law of inertia

• Newton's law of universal gravitation

Tags

NGSS.MS-ESS1-2

Of the following, which is a statement of Newton's second law of motion?

• An object's acceleration depends on its mass and the net force acting on the object.

• An object's kinetic energy depends on its mass and speed.

• 
  The force of gravity between two objects depends on their masses and the distance between them.

• For every force on one object by a second, there is an equal and oppositely direct force on the second object by the first.

Answer explanation

Newton's second law can be expressed by F = ma, where F is the net force on the object, m is the object's mass, and a is the object's acceleration.

Tags

NGSS.MS-PS2-2

Which of the following is a valid reason for protecting the habitats of certain species, such as the Preble's meadow jumping mouse?

• to eliminate the negative effects of deforestation

• to prevent a reduction in biodiversity

• to prevent a decrease in the food supply of hawks

Answer explanation

One reason to protect endangered species is to protect biodiversity. A diverse gene pool prevents inbreeding and produces a balanced ecosystem.

Tags

NGSS.MS-LS2-4

NGSS.MS-LS2-5

Students are completing a lab in which they investigate the impact of soil pH on the growth rate of grass. This lab connects which two science disciplines?

• physics and space science

• physics and biology

• chemistry and biology

Answer explanation

This lab illustrates the interconnectedness between soil acidity (chemistry concept) and nutrient availability (biology concept).

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-4

Which of the following is measured by a barometer?

• atmospheric humidity

• atmospheric pressure

Which of the following is most commonly used to monitor the path of a hurricane on the open ocean?

• Weather balloons

• Satellite imagery

• Radar tracking

• Buoy data

What is a student most likely measuring if she is using a wind sock?

• Wind Speed

• Wind direction

Mild rain or snow followed by warmer temperatures often corresponds with which type of weather front?

• stationary

• occluded

• warm

Answer explanation

Warm fronts bring gentle precipitation and mild weather.

Tags

NGSS.MS-ESS2-5

Occluded fronts form when a warm air mass is caught between two cold air masses, leading to strong, shifting winds and heavy precipitation.

• True

• False

Tags

NGSS.MS-ESS2-5