Unit 3 Science Test 2 5 21

Cars, bicycles, and people are all objects that can be in motion. What is true about motion?

• An object in motion is accelerating.

• Motion is the change in position of an object.

• Gravity and friction are responsible for all motion.

• An object in motion has speed, but it does not have velocity.

Objects that vibrate make energy. Which type of energy results from vibrations that travel through the air?

• chemical

• electrical

• potential

• sound

Which of these is a unit of speed?

• seconds per gram (sec/g)

• milliliters per second (mL/sec)

• grams per milliliter (g/mL)

• meters per second (m/sec)

• Taco Bell is the unit of speed

In which example is a force causing an object to accelerate?

• a train moving at constant speed around a curve in a track

• a rock sitting on a ledge at the top of a mountain

• a soccer ball sitting on the ground

• a girl riding a bicycle at a constant speed along a straight path

The total energy of water as it falls from a waterfall is which type of energy?

• chemical

• mechanical

• kinetic

• potential

Tia is walking her dog at a constant rate. They keep a constant rate as they turn a corner. Why has their velocity changed?

• because their speed changed

• because their direction changed

• because their position changed

• because their force changed

What type of energy change takes place as a car burns fuel to race down a track?

• potential energy to stored energy

• kinetic energy to potential energy

• stored energy to kinetic energy

• mechanical energy to kinetic energy

A roller coaster speeds up as it travels downhill and then slows as it enters a curve. Which statement best describes the motion of the roller coaster during this trip?

• The roller coaster accelerates throughout the trip.

• Velocity changes, but acceleration remains constant.

• The velocity of the roller coaster remains constant.

• The speed of the roller coaster remains constant.

If a child is rolling straight down a hill at a constant speed. What is changing as the child rolls?

• acceleration

• position

• speed

• velocity

Ang has a pogo stick. When he jumps on it, the spring squeezes toward the ground and then moves back to its starting position.

The potential and kinetic energies of the spring are forms of which type of energy?

• magnetic energy

• chemical energy

• electrical energy

• mechanical energy