Download Motion Study Guide

1.
Motion Study Guide
What does it mean for an object to be in motion?
WHEN AN OBJECT’S DISTANCE FROM ANOTHER OBJECT CHANGES. WHEN IT MOVES FROM A REFRERNCE POINT
2. What is velocity? Give an example of a velocity.
THE SPEED AN OBJECT IS TRAVELING AND THE DIRECTION IT IS TRAVELING. EX: 75 MPH NORTH
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What are possible SI units of measurements for speed?
METER/SECOND (CAN BE KM/HOUR)
What is the basic SI unit for length?
METER (M)
Is there a relationship between speed, distance, and time? If so, what is it?
YES THE SPEED IS FOUND BY DIVIDING DISTANCE BY TIME; S=D/t
If you are showing the speed of an object on a line graph, what should you label the X and Y axis?
Y-AXIS: DISTANCE
X-AXIS: TIME
What is the slope of a line? What does it tell you? How do you calculate it?
THE STEEPNESS OF THE LINE, THE ANGLE THAT IS CREATED BETWEEN IT AND THE X-AXIS
What does a horizontal slope tell you?
NO ACCELERATION; OBJECT MOVING AT A CONSTANT SPEED
What two things can change to cause acceleration to occur?
SPEED & DIRECTION
What type of line shows acceleration?
DIAGONAL
What is acceleration? What is deceleration? Give an example of each.
ACCELERATION: INCREASE IN SPEED EXAMPLE: RUNNER BEGINNING A RACE
DECELERATION: DECREASE IN SPEED EXAMPLE: RUNNER ENDING A RACE
What is the formula used to calculate acceleration?
a=SF – Si/T OR a=f/m
What is inertia? What law is sometimes called the “law of Inertia”?
OBJECT’S RESISTANCE TO CHANGE MOTION; NEWTON’S 1ST LAW
Briefly Explain Newton’s 1st, 2nd, & 3rd Laws of Motion.
1ST: OBJECTS WILL CONTINUE TO DO WHATEVER THEY ARE DOING UNTIL AN UNBALANCED FORCE
CHANGES IT
2ND: THE AMOUNT OF ACCELERATION IS AFFECTED BY THE MASS AND FORCE THAT IS APPLIED; IF YOU
INCREASE THE MASS THE ACCELERATION WILL DECREASE; IF YOU INCREASE THE FORCE THE ACCELERATION
WILL INCREASE
3RD: FOR EVERY ACTION THERE IS AN EQUAL & OPPOSITE REACTION
Which of Newton’s laws explains the relationship between force, mass and acceleration? What is the relationship?
2ND: THE AMOUNT OF ACCELERATION IS AFFECTED BY THE MASS AND FORCE THAT IS APPLIED; IF YOU
INCREASE THE MASS THE ACCELERATION WILL DECREASE; IF YOU INCREASE THE FORCE THE ACCELERATION
WILL INCREASE
How do you calculate acceleration and force according to Newton’s 2 nd law?
a=f/m
What is the action-reaction principle?
APPLYING A FROCE TO ONE OBJECT CAUSES THAT OBJECT TO APPLY A FORCE BACK
What is momentum? What are the basic units of momentum?
HOW HARD IT IS TO STOP AN OBJECT THAT IS IN MOTION kg *m/s
Explain the law of conservation of Momentum?
MOMENTUM IS NOT LOST WHEN TWO OBJECTS COME IN CONTACT WITH EACH OTHER; IT IS COMBINED
A 300-N force acts on a 25-kg object. The acceleration of the object is ____.
a=F/M
=300N/25KG
=12kgm/s2
A 3,000-N force acts on a 200-kg object. The acceleration of the object is ____.
a=F/M
=3000N/200KG
= 15Nkg
22. What are the different types of friction? Explain each one.
ROLLING: HAPPENS BETWEEN A ROUND AND FLAT OBJECT
STATIC: KEEPS AN OBJECT FROM MOVING
SLIDING: KEEPS TWO SOLID OBJECTS FROM SLIDING ON EACH OTHER
FLUID: CREATED WHEN AN OBJECT MOVES THROUGH A LIQUID OR GAS
23. What happens when balanced forces act on an object? What happens when they are unbalanced?
BALANCED: NOTHING, THE OBJECTS REMAINS STATIONARY
UNBALANCED: THE OBJECT MOVES IN THE DIRECTION THAT THE STRONGER FORCE IS MOVING IN
24. Draw a picture of balanced forces acting on an object.
50N
50N
25. Draw a picture of unbalanced forces acting on an object.
50N
100N
What do the following units represent? Use D for distance, T for time, S for speed, or A for acceleration.
D 1. 14 km
T 4. 6 hours
D_ 7. 14 mi
D 10. 1.4 m
S 2. 30 m/s
S 5. 12 cm/s2
T8. 3.2 sec
A 11. 6 cm/sec/sec
T 3. 34 min
S 6. 150 mph
D9. 25 ft
A 12. 3 km/hr/sec
13. At exactly 2:00 pm, Speedy the Snail crawls onto a meter stick at the 10 cm mark. If he reaches the 65 cm mark at
exactly 2:10 pm, what is his speed?
S = D/T
=55 cm/10min
=5.5 cm/min
14. A car travels 300 km in six hours. What is the speed of the car?
S = D/T
= 300 km/ 6 hrs
= 50 km/hr
15. A golf ball travels at 16 m/s, while a baseball moves at 7 m/s. The mass of the golf ball is 0.045 kg and the mass of the
baseball is 0.14 kg. Which has the greater momentum?
GOLF BALL: p = mv
= (.045 kg)(16m/s)
= .72 (kg)(m)/s
BASEBALL: = (.14 kg)(7 m/s)
= .98 (kg)(m)/s
BASEBALL HAS MORE MOMEMENTUM
16. A steel ball whose mass is 2.0 kg is rolling at a rate of 2.8 m/s. What is its momentum?
p = mv
= (2.0 kg)(2.8 m/s)
= 5.6 kg*m/s
17. A race car leaves the starting line and travels 36000 m in the first 600 seconds of the race. They are then forced to take
a pit stop and don’t go anywhere for 250 seconds. After the pit stop, they finish the race, going 24500 m in 350
seconds.
a. What is the car’s average speed during the first part of the race (before the pit stop)?
S=D/t
= 36000m / 600 s
= 60 m/s
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d.
What is the car’s average speed during the pit stop?
S=D/t
= 0 m/ 250 s
= 0 m/s
What is the car’s average speed after the pit stop?
S=D/t
= 24500m / 350 s
= 70 m/s
What is the car’s average speed for the whole trip?
S=Total Distance/ total time
= (36000m + 0m + 24500m) / (600s + 250s + 350s)
= 60500m / 1200 s
= 50.42 m/s
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Time (s) RUN
0
1
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4
5
Distance (m) RISE
0
2
8
18
32
50
a.
b.
Graph the data.
What does this graph represent?
The slope of the line
c.
What is the slope of the line in this graph (show your work)?
Slope = Rise/Run
=
19. Brittney pushes Haley who sitting on a swing. Haley has a mass of 500 kg and accelerates at a rate of 40 m/s2. Find the
force exerted by Brittney.
F = ma
= (500 kg)(40 m/s2)
= 20,000 N