Equal and Unequal Forces

Below lists descriptions of forces. Identify which row describes equal forces and which describes unequal forces.

Groups:

(a) Equal Forces

,

(b) Unequal Forces

• They change patterns of motion.

  Objects speed up, slow down, or change direction.

• Forces are balanced.

  Objects do not change their motion.

Which actions will make moving the cart in one direction easiest for the students?

• Student 1 pulls the cart to the left. Student 2 pulls the cart to the right.

• Student 1 pulls the cart to the left. Student 2 pushes the cart to the left.

• Student 1 pushes the cart to the right. Student 2 pushes the cart down.

• Student 1 pushes the cart to the right. Student 2 pulls the cart up.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

Students design an experiment to determine how much force is needed to move blocks of wood of different masses slowly across a lab table. Which procedure should students include in their design?

• Conduct five trials, using a different scale to pull each block of wood.

• Conduct five trials, pulling a different side of each block each time

• Conduct five trials, using a different table for each trial

• Conduct five trials, pulling each block of wood in the same way for each trial

Tags

NGSS.MS-PS2-2

The diagrams show two trials of an experiment in which a spring scale was used to measure force. This experiment can be used to determine —

• how mass affects the force needed to move objects

• how force affects the mass of two objects

• how the force used to pull a dictionary affects the mass of a box of marbles

• how the mass of a box of marbles affects the mass of a dictionary

Tags

NGSS.MS-PS2-2

Play media comment. A student uses a spring scale to pull a 50 gram block across a wood desk. Then the student pulls the block the same distance across surfaces of carpet, sandpaper, and glass. Which question is this investigation most likely designed to answer?

• How do blocks of different sizes react to force?

• How do different surfaces affect the amount of force needed to move a block?

• How do blocks affect spring scales?

• How does the mass of a block change when it is pulled across a desk?

Tags

NGSS.MS-PS2-2

Some students wanted to find out if a tennis ball and a baseball dropped from the

same height hit the ground at the same time. This investigation tests the effect of

which of the following?

• Wind

• Friction

• Gravity

• Magnetism

Tags

NGSS.MS-PS2-4

Using the table below, what is the connection between the starting height and how far the car rolled?

• The lower the starting position on the ramp, the farther the car rolled

• The higher the starting point on the ramp, the farther the car rolled

• The ramp has no effect on how far the car rolled

• The higher the starting position on the ramp, the faster the car roll

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-4

To move the wagon towards the door, it should be pushed in the direction indicated by which arrow?

• A

• B

• C

• D

Tags

NGSS.MS-PS2-2

A student pushes a wagon, and it begins to move in the direction shown. Describe the forces acting on the wagon.

• • The forces are equal because the wagon starts to move.

• • The forces are unequal because the wagon starts to move.

• • The force of gravity is pulling the wagon forward.

• • The metal parts of the wagon are attracted to a magnet.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

Which term best describes the forces acting on the box shown?

• Unequal

• Gravity

• Equal

• Unbalanced