Co-Taught General Science - Topic 3 Review

Daylon’s family just bought a new puppy, and Daylon decided to take him for a walk. He put the puppy in a wagon and pulled the wagon along the sidewalk. From which of these reference points does the puppy appear to be moving?

• Daylon

• the wagon

• the sidewalk

• the puppy’s collar

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

• Noncontact

• Gravity

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.

Two school classes are playing tug-of-war with a rope. One class pulls on the rope with a 75 N force to the left, while the other pulls with a 40 N force to the right. Which two statements describe this situation?

• The forces are balanced, and the rope does not move

• The forces are unbalanced, and the rope will move to the left.

• The net force on the rope is 115 N to the right.

• The net force on the rope is 35 N to the left.

You might have noticed that a feather falls slowly toward the ground, while a ball falls rapidly. Which statement correctly explains the motion of these objects?

• The ball does not experience fluid friction as it falls

• Gravity is the only force acting on the feather and the ball.

• The acceleration of the ball and feather are the same

• The feather experiences more fluid friction than the ball.

Nicki rides her bike at a constant speed for 6 km. That part of her ride takes her 1 hour. She then rides her bike at a constant speed for another 9 km. That part of her trip takes her 2 hours. What is her average speed?

• 3.00 km/h

• 5.00 km/h

• 5.25 km/h

• 7.50 km/h

Susan ran a 400-m sprint at a track meet, and her final time was 65 s. She reported that her velocity in the race was 6.15 m/s. Susan’s statement was inaccurate because she mentioned only

• direction

• acceleration

• speed

Susan ran a 400-m sprint at a track meet, and her final time was 65 s. She reported that her velocity in the race was 6.15 m/s. Susan’s statement was inaccurate because she mentioned only speed. She did not include _______________, which is also a part of velocity.

• acceleration

• speed

• direction