SCNC 102 Final Exam

Unit 1, 2, 3, and 4

T or F: A referent is a familiar object one can use to describe the property of a different object.

True

T or F: The triangle symbol means “proportional to.”

False

Why are equations useful for solving real world problems?

They let us predict outcomes based on known relationships

Which of the following (length, volume, time, and mass) are fundamental units of measurement?

Lenth, time, and mass

When something cannot be directly observed, it can be represented by a

model

The property of volume is a measure of

how much space the object occupies

A specific relationship between variables that you can observe repeatedly is a scientific

principle

An event with two situations with all influencing factors identical except one is a

controlled experiment

1 m=___ cm

100 cm

T or F: An object moving at 20 m/s accelerates when its direction of movement changes.

True

T or F: Newton’s second law states that if an unbalanced force acts on an object, it will move at constant velocity.

False

T or F: The reason a moving object slows down is that its foce of motion gradually runs out

False

T or F: Astronauts experience a weightless condition when they are in orbit

False

T or F: The force of gravity near the surface of Earth is 9.8m/s²

False, that is acceleration

Ignoring air resistance, the velocity of a fallin object is

constantly increasing

A heavy object and a light object are dropped from the rest at the same time on a planet with no air (vacuum). The heavier object with reach the ground

at the same time as the lighter object

T or F: The attractive force a 70 kg person exerts on Earth is much, much smaller that the force Earth exerts on the person

false

The pound is an English unit of measure; its SI counterpart is the

Newton

Suppose that a rock tied to a string is swinging in a circle. If the string length is decreased so that the length is halved by the same speed is maintained, then the force now exerted on the string is

double

A skateboarder pushes on the ground with her foot. She and the skateboard accelerate down the sidewalk due to the force

between the skateboard wheels and the groud

In referring to how much matter an object contains, we use the term

mass

The velocity is always ___ to the line of a circle

tangent

best definition of a measurement

A comparison of someting to a standard unit

Everything that happens in the universe can be traced to interactions of

matter and gravity

The tendency of a moving object to remain in unchanging motion in the absence of an unbalanced force is called

inertia

A heavy cannonball and a lighter bowling ball were dropped at the same time from the top of a building. At the instat before the balls hit the sidewalk, the cannonball has greater

momentum

T or F: The only kinematic variable that is shared between the horizon motion and vertical motion is the final speed of the object

False

A ship travels at a nautical speed of 40 knots. Given that 1 knot is 1.85 km/hr, 1hr is 60 min, 1 min is 60 s, and 1 km is 1000m, how would you determine this speed in m/s?

40×1.85/60/60×1000

A sprinter accelerates from rest at 3.8 m/s² along a straight track. You want to determine how far the sprinter travels before reaching a speed of 9.5 m/s. Which equation should you use?

v_f²=v_i²+2ax

T or F: The momentum of an object remains the same unless an unbalanced force acts on it.

True

A beat frequency occurs when two sound waves

have slightly different frequencies

T or F: Liquid water at 0 degrees C must give up energy to become ice at 0 degrees C.

True

Kinetic energy refers to

energy of motion

Two students stand poised to leap off a high dive structure into a swimmin pool below. Pat is twice as massive as Chris. What is true?

Pat did twice as much work climbing to the top of the structure.

The heat needed to warm one gram of water one Celsius degree is called a

calorie

A statement that the energy sypplied to a system in the form of heat, minus the work done by the system, is equal to the change in internal enegy, represents the

First law of thermodynamics

The characteristic of a sound wave that you interpret as loudness is related to

amplitude

In longitudinal waves, the medium

Vibrates in the same direction as the wave is moving

The transfer of heat that occurs when energy moves from molecule to molecule by direct contact is called

conduction

The amount of hear needed to increase the temperature of 1 gram of a substance 1 degree Celcius is known as

specific heat

A sound that is perceived as twice as loud requires

ten times the intensity

The higher the frequency of a sound wave

the higher the pitch

Resonance occurs at a

natural frequency

Through which medium will sound travel most rapidly?

Steel

T or F: Sound moves through air as transverse waves

False

The process of heat transfer that requries gravity is

convection

T or F: The molecules of a gas are much farther apart than molecules in a solid or liquid.

True

T or F: You do significantly more work on yourself against gravity when you run up the stairs than when you walk slowly.

False

At the end of time, when we reach maximum entropy of the universe, this will be known as

heat death of the universe

The watt (W) is a unit of

power

When riding in a car moving away from a stationary loud horn, the observed sound wave has a pitch that is seemingly

becoming lower

T or F: Your electric bill for 1500 kilowatt-hours is a charge for the power you used that month

False

When a light bulb is rated at 60 W, it means that

each second, the bulb converts 60 J of electrical energy into heat and light

T or F: Water turns into rounded droplets on wax paper because its cohesive forces are greater than the adhesive forces

True

T or F: The degrees on the Celcius scale are larger that the degrees on the Fahrenheit scale

True

When the trough of one wave collides at the same time and place as the crest of an otherwise identical wave,

destructive interference occurs

T or F: The nutritionist’s capital “C” Calorie is more accurately known as a kilocalorie.

True

Molecules in a solid

are held in nearly fixed positions by strong attractive forces

The time that is required for an oscillatiing object to complete one full cycle is called

period

Which device relies on work coming out?

Heat engine