Balanced and Unbalanced Forces

For an investigation, a student measures the speed of a cart as it rolls down a ramp. The student then records datat in the table below. Which of these best explains the student's data?

• The speed of the cart decreases as the cart rolls down the ramp because of friction between the cart and the ramp.
• The speed of the cart increases as teh cart rolls down the ramp because the force acting on the cart is greater than the the force of gravity.
• The speed of the cart increases as the cart rolls down the ramp because the forces acting on the cart are unbalanced.
• The speed of the cart decreases as the cart rolls down the ramp because the forces acting on the cart are balanced.

Tags

NGSS.MS-PS2-2

Two cars with different masses travel at the same speed down a hill towards a stop sign. What will happen when both cars apply brakes at the same time to stop?

• The car with the smaller mass will require less force to stop than the car with the larger mass.
• The car with the larger mass will maintain its velocity while traveling down the hill. 
• The car with the smaller mass will take longer to stop than the car with the larger mass.
• The car with the larger mass will have less inertia than the car with the smaller mass. 

Tags

NGSS.MS-PS2-2

In the classroom demonstration shown below, a rubber ball is dropped from Position 1. The ball bounces as shown. At which of these positions does the ball have both the greatest kinetic energy and the least potential energy?

• Position 1
• Position 2
• Position 3
• Position 4

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

Which description is a correct interpretation of the graph?

• A car travels at a constant speed of 15m/s for 2 minutes. The car increases its speed from15 to 25 m/s during the next minute and then travels at a constant speed of 25 m/s for 2 more minutes.
• A car travels at a constant speed of 15 m/s for 2 minutes. The car decreases its speed from 15 to 25 m/s during the next minute and then travels at a constant speed of 25 m/s for 2 more minutes.
• A car increases its speed from 15 to 25 m/s for the first 2 minutes then travels at a constant speed for 5 minutes then increases its speed to 30 m/s during the next 5 minutes. 
• A car decreases its speed from 25 to 15 m/s for the first 2 minutes then travels at a constant speed for 5 minutes then increases its speed to 30 m/s during the next 5 minutes. 

Tags

NGSS.MS-PS3-1

A student walks 2 km in 30 minutes. What is the student's average speed in km/h? 

• 2
• 4
• 6
• 8

Some students measure the acceleration of a wheeled cart being acted on by varying forces. The students record their data in the table shown above. According to the data table, how much force is acting on the cart when the students measure an acceleration of 2.6m/s2?

• 13N
• 7N
• 8N
• 12N

Tags

NGSS.MS-PS2-2

The diagram below shows a hot air balloon rising. Propane gas tanks are seen at the bottom of the balloon. What energy transformations occur when propane gas is used to lift the balloon?

• Mechanical --> light --> chemical
• Chmical --> mechanical --> thermal
• Thermal --> chemical --> light
• Chemical --> thermal --> mechanical

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

Sometimes tectonics plates do not move easily past one another, and the plates become stuck. Forces build up, and when the plates finally move, tension is released, as shown below. The sudden movement of the plates is caused by ____. 

• the mass of the plates
• the weight of the plates
• unbalanced forces 
• gravitational force

Tags

NGSS.MS-PS2-4

The diagram below shows a boat moving north in a river at 3 m/s while the current in the river moves south at 1 m/s. How will the boat be affected if it enters a part of the river where the current is moving south at 2 m/s?

• The boat will move slower.
• The boat will move faster. 
• The boat will stop.
• The boat will move to the west.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A student lets a toy car roll four times down a ramp that is 1m 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