Physics

Describe the relation between the horizontal and vertical components of a projectile’s velocity.

• equal

• directly proportional

• independent of each other

• inversely proportional

Identify the horizontal acceleration of a projectile after it is fired.

• zero

• constant

• directly proportional to acceleration due to gravity

• dependent on the vertical acceleration

Neglecting air resistance, the initial horizontal velocity of a projectile is ____ to its final horizontal velocity

• equal to

• greater than

• less than

• directly proportional

Identify which is not an example of projectile motion.

• a leaf falling from a tree

• a stone thrown into a lake

• a basketball being thrown

• throwing an aluminum can into the recycling bin

A mover of household goods wants to push a heavy bureau at rest on the floor across the floor. He puts his shoulder against the bureau and begins to push. He gradually increases the force of his push until the bureau moves when he keeps the pushing force constant. Describe what happens to the force of friction.

• decreases then increases

• remains the same

• increases then decreases

• continues to increase

Describe the coefficient of kinetic friction.

• it is a type of contact force.

• It is measured in newtons

• It depends on the normal force.

• It depends on the composition and qualities of the surfaces in contact.

How does the sound travel from its source to your ear?

• by changes in air pressure

• by electromagnetic waves

• by vibrations in wires or strings

• by infrared wavs

Indicate what the frequency of the sound wave determines.

• amplitude

• intensity

• power

• pitch

Determine the best angle to hit a baseball as far as possible.

For each statement below, write true or rewrite the italicized part to make the statement true.

A. Sound wave travels fastest through a gas.