Motion and Force Quiz

Suppose a bulldozer is being hauled on the back of a flatbed truck at 50 km/h to a construction site. From which reference point would the bulldozer not appear to be moving?

• the road

• a traffic light

• the truck driver

• a roadside tree

Carmen is helping load furniture and boxes onto a moving truck. She picks up boxes of her things, places them on a cart, and pushes the cart to the moving van. Which term best describes the type of force Carmen is using?

• contact

• friction

• gravity

• noncontact

Ahmed saw all of these things as he walked to school this morning. Which one is an example of a force pushing downward toward the ground?

• A bird sat on a telephone wire.

• A woman moved her child from one place to another in a wagon.

• A man pulled weeds in his garden.

• A dog tugged on a rope held by a child.

Mr. Wang works in a recycling center. Recyclable materials arrive at the center mixed together. Workers use magnets to separate steel cans from other items. Which two statements are true about the force between a steel can and a magnet?

• Gravity pushes the can toward the magnet.

• The force between the can and the magnet is a noncontact force.

• The attraction between the can and the magnet is a pull.

• The attraction between the can and the magnet is a push.

Look at the middle diagram, where the large dog and the small dog tug on the rope. Which statement correctly explains the amount and direction of the net force acting on the rope, and in which direction the rope will move?

• The net force is 8 N to the left, and the rope will move to the right.

• The net force is 8 N to the left, and the rope will move to the left.

• The net force is 32 N to the left, and the rope will move to the left.

• The net force is 32 N to the right, and the rope will move to the right.

Explain whether the forces shown in each diagram are balanced or unbalanced. Use math-based evidence to support your claim for each diagram.

Vivian went on a bicycle trip through Germany with her family. One afternoon, she rode her bicycle along a long, flat road at a constant speed for 24 kilometers (km). The ride took her 1.2 hours (h). At what speed did she ride her bicycle?

• 0.05 h/km

• 20 mi/h

• 20 km/h

• 28.8 km•h

Pace left home at 8 AM to spend the day at an amusement park. He arrived at the park, which was 150 km from his house, at 10 AM. Pace explained that his speed was 38 km/h, which was a/an (accelerated / directional / instantaneous / average) speed, but the fastest speed he went was 60 km/h, which was a/an (directional / instantaneous / accelerated / average) speed.

• average

• instantaneous

An antelope is being chased across the savannah by a hungry lion. The lion runs at a constant speed. How might the antelope use its velocity to escape the lion? Choose the three statements that apply.

• It can run at the same speed but change direction.

• It can run in the same direction but increase its speed.

• It can both increase speed and change direction.

• It can decrease speed but continue running in the same direction.

Anna hits a golf ball, and it soars through the air toward the green. It travels in an arc over the ground. Which statement does not describe the ball’s acceleration before it stops?

• It increases speed.

• It decreases speed.

• It changes its overall direction.

• It moves in the same direction.