1. 1. Which object listed above is exerting the greatest pressure?
Mass of object (kg)
Length over which force is acting (cm
Area of surface on which force is acting (cm3)
Force exerted by the object (N)
Picture hanging on a wall 9
2.5 1
88.2
Bowling ball on the floor 6
0.5 59
Box on table 25 35
1,225
245
Person standing on a bridge 50
225
490
1. Which object listed above is exerting the greatest pressure?
A. the picture hanging on the wall
B. the bowling ball on the floor
C. the box on the table
D. the person on the bridge

2. 2. Gretchen’s portable CD player always skips when someone bumps into her desk. She sees that it skips because it slides too easily on smooth surfaces. What could Gretchen do to solve the sliding problem?
She could add a board to widen the area of her desk.
She could add rubber circles to the bottom of the compact
disc player.
C. She could attach an adapter to allow her to plug the player
into a wall socket.
D. She could attach felt cushions to the bottoms of her desk’s
legs to keep the desk from rocking.

3. 3. During a thunderstorm, lightning strikes Earth when
A. clouds have no charge
B. The static positive charge built up in the tops of clouds reunites with the static negative charge built up in the bottoms of the clouds.
C. A static negative charge builds up on Earth, inducing a static positive charge in the bottoms of clouds, and electrons flow from Earth to the clouds.
D. The static negative charge built up in the bottoms of clouds induces a positive charge on Earth, and electrons flow from the clouds to Earth.

4. 4. The region around a magnet where the magnetic force is exerted is known as its
Magnetic pole
Lodestone
Magnetic field
Magnetic domain

5. 5. Read the following passage and then complete the questions which follow.
Speed refers to how fast an object is moving. Motion is a change in the position of an object when compared to a nonmoving reference point. Velocity is the speed of an object and its direction of motion. A change in velocity is called acceleration. A decrease in velocity is called negative acceleration or deceleration. The rate of acceleration depends on both the amount of force used and the mass of the object being moved.
Force is push or pull that is exerted on an object. When a strong enough force is applied to an object, the object’s motion changes. If you apply a small force to a massive object (like a car), you will cause a small amount of acceleration. If you apply a large force to a small object (like a tennis ball), you will cause a large amount of acceleration. Any object that is moving in a straight line at a constant speed is not accelerating.

6. Circle the answer that correctly completes each sentence.
A car sitting at a stoplight (is/is not) accelerating.
A car driving at 50 miles per hour for a long time on a straight stretch of highway (is/is not) accelerating.
A car that begins to move after a stoplight turns green (is/is not) accelerating.
A car slowing down as it pulls into a parking space (is/is not) an example of negative acceleration.

7. 20. Oil floats on water, therefore, what can you determine about the density of water?

8. 20. Oil floats on water, therefore, what can you determine about the density of water?
Oil is less dense than water, therefore it floats on water. The density of water is 1g/cm3.
Other examples- gasoline, diesel, radiator fluid, baby oil, plastic, styrofoam, wood