24-25 7th Grade 3rd Six Weeks Assessment

Jamie and Alex are participating in a straight-line race. Jamie runs from point A to point C, a total distance of 100 meters, in 40 seconds. Alex runs from point A to point B and then back to point A, covering the same total distance of 100 meters, also in 40 seconds. Both runners start at point A. Jamie ends at point C, and Alex ends back at point A. Which statement below is most true of this race?

• Jamie and Alex have the same velocity because they both travel 100 m total.

• Jamie and Alex have different velocities because their displacements are different. Jamie ends at point C, while Alex ends at point A.

• Jamie and Alex have the same velocity because they both travel at 100m/40s.

• Jamie and Alex have different speeds because their displacements are different. Jamie ends at point C, while Alex ends at point A.

For each table below, drag and drop the labels 'Velocity' and 'Speed' into the rows that accurately describe each. Items can be used more than once. Move ONE correct answer to each box.

Which of the following is the BEST example of unbalanced forces causing a skateboarder to demonstrate Newton's First Law of Motion?

• 680 Newtons of gravity pulls downward on the person and skateboard, while 680 Newtons of force push upward from the ground.

• The force of the skater pushing against the ground is 120 Newtons to the right, while the force of air resistance and friction acting against the skater's push is 100 Newtons to the left.

• The force of the skater pushing against the ground is 120 Newtons to the right, while the force of air resistance and friction acting against the skater's push is 120 Newtons to the left.

• 850 Newtons of gravity pulls down and to the right on the person and skateboard because they are on a slanted hill, while 680 Newtons of force push upward from the ground and a huge wind gust of 170 Newtons pushes against them to the left.

Why does the answer you selected above show unbalanced forces demonstrating Newton's First Law of Motion?

• Because the net force is greater than zero and Newton's First Law tells us that heavier objects need a larger force to move them.

• Because the net force is equal to zero and an object at rest stays at rest unless acted on by an outside force.

• Because the net force is less than zero and an object at rest stays at rest unless acted on by an outside force.

• Because the net force is greater than zero and an object at rest stays at rest unless acted on by an outside force.

A toy car is rolled down a ramp to the right. What will happen to it if nobody tries to block or stop it?

• Friction, the force of the ground pushing up, and air resistance are forces pushing back against the force of gravity pulling it down and to the right on the ramp, and so it will eventually stop.

• It will continue on until the force of gravity pushes back to the left at an equal force.

• Newton's Laws state that an object in motion stays in motion unless an outside force acts upon it, and so it will continue on forever until someone or something physically blocks it.

• Its mass times the velocity will give the amount of seconds until it stops.

Which of the following shows thermal heat transfer into using radiation in the image below?

• A and C

• A and B

• C only

• A only

In the Earth's mantle, magma does not just stay still. The magma at the innermost part of the mantle rises, cycles outward, and the magma at the top sinks down, creating circular patterns of motion. What is the cause of this motion?

• Potential energy

• Thermal energy

• Kinetic energy

• Gravitational energy

Which of the following is used for the energy transfer in the mantle?

• Mass force

• Speed

• Conduction

• Convection

Heat transfer follows predictable patterns and rules. When you open a window in a hot room, and it is cooler outside than it is inside, which way would you expect the air to move based on the temperature differences?

• The air would flow back and forth.

• The air would stay still.

• The air would flow from outside to inside.

• The air would flow from inside to outside.

The image below is of two tanks of water (one hot and one cold) connected by a pipe. Which of the following statements is the MOST accurate about energy transfer here?

• The heat will flow from the hot to the cold, and it will not stop flowing.

• The hot tank will stay hot and the cold tank will stay cold; no heat will be transferred.

• The heat will flow from the hot to the cold, and it will eventually stop when the temperatures are all equal.

• The heat will flow from the cold to the hot, and it will eventually stop when the temperatures are all equal.