Physics Unit 1 Review

What is dynamics?

motion with regard to force

v= -3.75 m/s positive motion negative motion no motion

negative motion

What does a constant acceleration mean?

the velocity increases at the same rate each second.

average speed

total distance/time

Suppose a car is moving in a straight line and steadily increases its velocity (or speed). It moves from 30 km/h to 45 km/h in 3 seconds. What is the car's acceleration?

45-30/3= 5 km/h/s

A truck traveling 30 m/s accelerates at a rate of 0.5 m/s^2 for 4 seconds. Find the final velocity? a. 240 m/s b. 64 m/s c. 32 m/s d. 15 m/s

c. 32 m/s

What is kinematics

Motion without regard for force

A negative acceleration means what?

Object is slowing down

Both velocity and speed use the same equation T/F

T

Since gravity pulls down, its direction is negative. T/F

T

distance is NOT dependent on direction. T/F

T

If a caterpiller takes 45 minutes to travel 3 meters across your driveway, what is its average speed? a. 0.67 m/min b. 15 m/min c. 0.067 m/min d. 135 m/min

c. 0.067 m/min

change in state of motion

acceleration

slope of a velocity vs. time graph represents the ____ of the object.

acceleration

Fred stands at the edge of the Grand Canyon and yells down to the bottom. If Velma, (standing at the bottom), hears Fred 2.6 seconds later, how deep is the canyon where she is standing? (Sound travels at 340 m/s) a. 0.008 m b. 884 m c. 130.77 m d. 0.77 m

b. 884 m

Check all of the following that are vector quantities. [mark all correct answers] a. speed b. velocity c. displacement d. distance e. time

b. velocity c. displacement

A measure of the amount of matter in an object

mass

how fast something moves

(speed) distance/time

What unit is used for gravity

10 m/s^2

What is the acceleration of a truck 12 seconds after starting from rest if the truck is now moving at 40 m/s2?

50 - 0/12 a= 4.17 m/s^2

What is scalar

A scalar quantity has only magnitude.

What is a vector?

A vector quantity has both magnitude (which is another word for size or the number) and direction.

What is distance?

How far something moves

Any time we have a distance vs time; a displacement vs. time; or a position vs. time graph, the ____ is the speed

slope

If a crab travels with an average speed of 5.70 km/year, how long will it take the crab to travel 100 km? a. 17.54 years b. 570 years c. 0.057 years d. 1.75 years

a. 17.54 years

What is the basic equation for acceleration

a= vf- vo/ tf - to

Formula for velocity

d/t

____ an object falling without any other influence than gravity

free fall

No matter which position you are asked about, the acceleration is ALWAYS ___

gravity.

Motion in a straight line is ______

linear

What unit is used for distance

m

What unit is used for acceleration

m/s^2

slope is a horizontal line positive motion negative motion no motion

no motion

v= 0 m/s positive motion negative motion no motion

no motion

What are fundamental units?

one that can be measured.

Speeding up" is _______ acceleration while "slowing down" is _____ acceleration.

positive negative

slope is diagonal toward the upper portion of the graph positive motion negative motion no motion

positive motion

What unit is used for time

s

Is distance scalar or vector? Why

scalar b/c doesn't depend upon direction

The slope of a distance vs. time graph is the ____

speed

Check all of the following that are scalar quantities. [mark all correct answers] a. speed b. velocity c. displacement d. distance e. time

speed distance time

instantaneous speed

speed at any instant

What is velocity?

speed with dirction

What is displacement

straight-line distance, how far the starting point is from the ending point.

Is velocity, scalar or vector

vector

Since gravity has both magnitude (-10 m/s2) and direction (down), it is a ___quantity.

vector

Is displacement scalar or vector? Why

vector b/c involves distance and direction

The slope of a displacement vs. time graph is __.

velocity

What are some examples of vectors?

velocity force momentum weight acceleration

A car going 75 m/s undergoes an acceleration of 5.0 m/s2 for 8 seconds. What is the final velocity of the car?

vf= 75 m/s + (5 m/s^2) (8)= vf= 115 m/s

What is another equation for velocity?

vf= vo + at

A dragster accelerates uniformly from rest to a speed of 90 m/s over a distance of 400 m. What is the average acceleration over that distance?

vo= 0m/s vf= 90 m/s d= 400m v^2f= v^2o + 2ad (90 m/s)^2 = (0m/s)^2 + (2) (a) (400m) Solve for a a= 10.13 m/s^2