Physics 11

Mid Year Review

Basic Skills (Sc. Not./Sig Figs/Unit Conversions/Graphing)

Convert the following to scientific notation in standard form

1)431261)______

2).00422)______

3)-7000003)______

4)-.00001504)______

5).0075 x 1035)______

6)970 x 10-46)______

7)-.000516 x 10-57)______

Round the following to the number of figures shown and convert to scientific notation in standard form

8)634000round to 2 figures8)______

9).0345round to 2 figures9)______

10)298.76 x 10-4round to 1 figure10)______

11)8.651 round to 2 figures11)______

Unit conversions

12)3500 mm into km12)______

13)22.3 metres/second into km/hr13)______

14)4584 secs to min & hours14)______

Indicate the number of significant figures in the number given

15)32100.015)______

16).0012316)______

17).2004017)______

18)7330.018)______

19)3200 kilometres19)______

20)125 physics students20)______

21).030021)______

Evaluate the following and use the correct number of significant figures in your answer

22)22.5 x 345622)______

23)23)______

24)24)______

25)9.02 + 4.5784 + 6.225)______

26)2301 + 834 + 3.526)______

27)27)______

28)(1.75)228)______

29) Graphing

Graph the following data on the graph below:

X / 1.2 / 2.2 / 3.3 / 4.2 / 5.3 / 6.2 / 7.4
Y / 3.5 / 4.4 / 5.6 / 6.4 / 7.3 / 8.3 / 9.2

a)Draw a slope triangle on the graph, and use it to determine the slope of the line from the graph

b)Estimate the y-intercept of the graph, and combine it with the slope to determine the equation of the line. Your answer should look like this: y=mx+b - write in your values for m and b.

Answers:

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Physics 11

  1. 4.3126x104
  2. 4.2x10-3
  3. -7.0x105
  4. -1.5x10-5
  5. 7.5
  6. 9.7x10-2
  7. -5.16x10-9
  8. 6.3x105
  9. 3.5x10-2
  10. 3x10-2
  11. 8.7
  12. 3.5x10-3 km
  13. 80.3 km/hr
  14. 76.4 min, 1.27 hr
  15. 6
  16. 3
  17. 5
  18. 5
  19. 2
  20. 3
  21. 3
  22. 77800
  23. 160
  24. 1.2
  25. 19.8
  26. 3138.5
  27. .742
  28. 3.06

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Physics 11

KINEMATICS REVIEW 1

Sketch a distance vs time graph for each of the following scenarios. If specific time, positions and velocities are given, label them on the graph.

  1. A car travelling north at a velocity of 50 km/h, slows down to 30 km/h when it enters a school zone.
  1. A boy walks away from the kitchen table, 4m to the right with a velocity of 2 m/s. He spends 6 s getting a bowl out of the refrigerator, and then walks back to the table at 1 m/s.
  1. At soccer practice the coach makes the players run back and forth between two lines, four times.

  1. The motion of two joggers is recorded in theposition-time graph below. Calculate theaverage velocity of jogger A and jogger B.
  1. Given the position-time graph below,determine which segment of the graph represents each of the following.

(a) zero velocity

(b) positive slope

(c) moving north with a uniform velocity

(d) zero slope

(e) moving south with a uniform velocity

(f) negative slope

Kinematics RVW Cont’d.

Questions:

Use the graph to answer questions 1. & 2.

1. Determine the velocity of the object from the slope.

2. What is the position of the object after 3.5 s

Use the graph to answer questions 3. & 4.

3. Determine the velocity of the object at 4 s.

4. Explain why the slope is zero between 5 s & 10 s.

Use the graph to answer questions 5. & 6.

5. What is the initial position of the object?

6. What is its velocity?

Use the graph to answer question 7.

7. What is the displacement of the object after 3.5 s? Show your work.

8. Graph the following on a d vs. t graph:

An object travels at 5.0 m/s for 4 s. It then stops for 3.0 s. Finally it returns to it’s initial position travelling -2.0 m/s for 10s.

9. Describe 2 differences in the slopes of the line. What conclusions can you make about the direction and steepness of the slope of d vs. t graph

  1. For each of the following time intervals, describe the motion of the object represented by the position-timegraph. Be sure to include directions when needed.

(a) 0 s–6 s

(b) 6 s–10 s

(c) 10 s–12 s

(d) 12 s–16 s

(e) 16 s–18 s

(f) 18 s–20 s

  1. Calculate the displacement for each of the time intervals in question 10.
  1. For each of the time intervals in question 10, identifythe slope of the line as positive, negative, or zero.
  2. What total distance did this object travel in 20 s?
  3. Match each of the following descriptions to theappropriate line.

(a) The object starts at the origin and travels south with uniform motion.

(b) The object starts 2 m [S] and travels northwith uniform motion.

(c) The object starts at the origin and travels north with uniform motion.

(d) The object starts 2 m [N] and travels southwith uniform motion.

  1. Use the graph below to fill in the chart below

During what time interval was the object moving thefastest? What direction was the object moving?

More Kinematics REVIEW

  1. A bike first accelerates from 0.0 m/s to 5.0 m/s in 4.5 s, then continues at this constant speed for another 4.5 s. What is the total distance traveled by the bike? 33.8 m
  1. A car traveling at 20 m/s when the driver sees a child standing in the road. He takes 0.80 s to react, then steps on the brakes and slows at 7.0 m/s2. How far does the car go before it stops? 44.6 m
  2. A car starts 200 m west of the town square and moves with a constant velocity of 15 m/s toward the east. Draw a graph that represents the motion of the car sorry, no graph.

a.Write the equation that represents the motion of the car. d = 15 t – 200 (if west is considered negative)

b.Where will the car be 10 minutes later? 8800 m

c.When will the car reach the town square? 13.3 s

  1. At the same time the car in #3 left, a truck was 400 m east of the town square moving west at a constant velocity of 12 m/s.

a.Add the truck’s motion to the graph you drew for question #4. sorry, no graph.

b.Write the equation that represents the motion of the truck. d = -12 t + 400

c.Find the time and place where the car passed the truck. 22.2 s; 133 m east of town

  1. A car is coasting backwards downhill at a speed of 3.0 m/s when the driver gets the engine started. After 2.5 s, the car is moving uphill at 4.5 m/s. Assuming that uphill is positive direction, what is the car’s average acceleration? 3.0 m/s2
  2. A car slows from 22 m/s to 3.0 m/s at a constant rate of 2.1 m/s2. How many seconds are required before the car is traveling 3.0 m/s? 9.04 s

8. An airplane starts from rest and accelerates at a constant rate of 3.00 m/s2 for 30.0 s before leaving the ground.

a.How far did it move? 1350 m

b.How fast was it going when it took off? 96 m/s

10. A brick is dropped from a high scaffold.

a.What is its velocity after 4.0 s? 39.2

b.How far does the brick fall during this time? 78.4 m

11. A tennis ball is thrown straight up with an initial speed of 22.5 m/s. It is caught at the same distance above the ground.

a.How high does the ball rise? 25.8 m

b.How long does the ball remain in the air? 4.6 s

  1. A bag is dropped for a hovering helicopter. When the bag has fallen for 2.0 s,

a.what is the bag’s velocity? 19.6 m/s

b.how far has the bag fallen? 19.6 m

Kinematics Review II

  1. Joe can run at 7.0 m/s. Sheila can run at 4.0 m/s. Joe gives Sheila a 40 m head-start. Using a distance vs time graph...

a) Determine how long it takes Joe to catch Sheila. 13.3 s

b) Determine how far Joe travels by the time he catches Sheila. 93.3 m

c) At what time will Joe be 10 m ahead of Sheila? 16.7 s

d) When Joe has run 200 m, how far has Sheila run? 154.3 m

e)Write equations for Joe’s motion and Sheila’s motion.Joe d + 40 = 7.0 t; Sheila d = 4.0 t OR Joe d = 7.0 t; Sheila d = 4.0 t + 40

  1. A motorcyclist accelerates from 3.0 m/s to 27 m/s in 4.0 s. What is his acceleration? 6.0 m/s2
  1. A car accelerates at 5.0 m/s2 from an initial velocity of 14 m/s. How long will it take to reach a velocity of 65 m/s? 10.2 s
  1. A car accelerates form rest at 12.0 m/s2 for 14.0 s.

a)How fast is it moving after 14.0 s? 168 m/s

b)How far has it traveled in this time? 1176 m = 1180 m

  1. A skier accelerates down a slope with an acceleration of 4.2 m/s2. She passes the first timing gate at 18 m/s. 6.0 s later she passed a second timing gate.

a)How fast is she going as she passes the second gate? 43.2 m/s

b)What is the distance between the gates? 184 m/s

  1. A motorcyclist starting from rest averages 24 m/s along a 500 m track. What was his acceleration? (Assume constant acceleration) 2.3 m/s2
  1. A block of wood was sliding along on level ice. Its initial speed was 18 m/s. If it took 15 seconds to come to a complete stop, what was the acceleration due to friction? –1.2 m/s2
  1. An object is dropped from rest near the surface of the Moon. The acceleration due to gravity on the Moon is 1.67 m/s2. What is the speed of the object after it has dropped 54 m? 13.4 m/s
  1. A skier passes a photogate traveling at 12 m/s. 30 m further down the slope she passes another photogate and is found to be traveling at 18 m/s. Assuming a constant slope what is the skier's acceleration? 3.0 m/s2
  1. An astronaut jumps off a 3.0 m ledge on the moon. What is the astronaut's speed as he hits the ground? 3.17 m/sWhat would be the final speed of someone jumping off a similar ledge on earth? 7.67 m/s(Assume negligible friction).
  2. 1A ball is thrown vertically upwards at an initial speed of 26 m/s. The acceleration due to gravity is -9.8 m/s2 (downwards!). How long will the ball take to reach its maximum height? 2.65 s What is its maximum height? 34.5 m
  1. An object is thrown vertically upwards at 24 m/s. The acceleration due to gravity is 9.8 m/s2.

a)Draw a velocity vs time graph representing the objects motion.

b)How high will the object be after 2.0 s? 28.4 m

c)How fast will the object be traveling after 2.0 s? 4.4 m/s

d)How long will it take for the object to reach its maximum height? (Hint: what do you know about the velocity of an object at its maximum height?) 2.45 s

e)What is the object’s maximum height? 29.4 m

NEWTONS LAWS AND FORCES

  1. What is the weight (Fg) of a 543 kg object on earth?
  1. What is the distance between two 20.0 kg objects that have a mutual force of gravitational attraction of 3.0 x 10-7 N?
  1. The constant G in the Law of Universal Gravitation has a value of 6.67 x 10-11 Nm2/kg2. Calculate the force of gravity between:

a) 100.0 kg person and the earth (Mass of earth = 5.98 x 1024 kg, Radius of earth = 6.38 x 106 m)

b) 100.0 kg person and the moon (Mass of moon = 7.35 x 1022 kg, Radius of moon = 1.74 x 106 m)

  1. A force of 120 N is needed to push a box along a road at a steady speed. If the force of gravity on the box is 250 N, what is the coefficient of kinetic friction between the box and the road?
  1. The coefficient of kinetic friction between a steel block and an ice rink surface is 0.0100. If a force of 24.5 N keeps the steel block moving at steady speed, what is the force of gravity on the block?
  1. A 20.0 N force is used to stretch various rubber bands. Calculate the amount of stretch that will occur, given each of the following spring constant.

(a) 200. N/m

(b) 100. N/m

  1. A 15 kg box is pulled by a 40N horizontal force. The kinetic coefficient of friction is 0.1 and the static coefficient is 0.2. Will the crate move? And if so, what is its acceleration?

ForcesReview cont’d

Problems:

  1. An average net force of 16 N acts on an object for 0.2 s causing it to accelerate from rest to 3.5 m/s. Determine the acceleration of the object. What is the mass of the object?
  1. A horizontal force of 90 N is required to push a 75 kg object along a horizontal surface at a constant speed. What is the magnitude of the force of friction?
  1. An object of mass 525 kg is 3.0 x 103km above the earth’s surface. The object is falling toward the earth because of the earth’s gravitational force on it. What is the gravitational field strength at this distance?
  1. On the surface of planet Rozo, which has a mass of 7.9 x 1025 kg, an object has a weight of 112 N and a mass of 75.0 kg. What is the radius of this planet?
  1. An 85 N object is pulled along a horizontal surface by a force of 32 N. The frictional force acting on the object is 14 N.

a) What is the net force acting on the object?

b) what is the acceleration of the object?

c) What is the coefficient of friction between the surfaces?

  1. A 2.5 kg object is pulled along a horizontal surface at a constant velocity of 2.0 m/s by a force of 3.0 N. What is the coefficient of friction between the surfaces?
  1. A vertical spring (k = 86.6 N/m) is stretched 8.5 cm when an object is placed on it.

a)What is the force acting on the spring?

b)What is the mass of the object?

  1. A 5.0 kg object rests on an incline plane at an angle of 25o. What is ?
  1. A 4.0 kg mass is acted upon by a net force of 10 N [R]. What is the acceleration of the mass?
  1. A 75 kg box is pulled across a floor with an applied force of 120 N [L] against a 75 N force of friction.

a) What is the net force acting on the box?

b)What is the acceleration of the box?

  1. An horizontal force of 15 N [E] is applied to a 2.0 kg mass, which gives it an acceleration of 3.0 m/s2 [E] sliding along a floor

a) What is the net force acting on the mass?

b) What is the force of friction experienced by the mass?

Answers

1) .914 kg2) 90 N3) 4.54 N/kg

4) 5.95 x 107m5) 18 N, 2.1 m/s2, 0.16, 6) 0.12

7) 7.36 N, .75 kg8) 44.4 N, 20.7 N9) 2.5 m/s2 [R]

10) 45 N [L], 0.60 m/s2 [L] 11) 6.0 N [E], 9.0 N [W]

Newtons Laws REVIEW

1.Aforwardmovingcariscoastingtoastoponastraight,levelroad.Thenetexternalforceonthecarmustbe

a)zero

b)forward

c)backward

d)downward

e)upward

2.TheaccelerationofamovingobjectisALWAYSinthedirection

a)oftheinitialvelocity

b)ofthefinalvelocity

c)ofthenetforce

d)ofthefrictionalforce

e)oppositetothefrictionalforce

3.Adynamicscartofmass0.20kg,initiallyatrestisacteduponbyanunbalancedforceof3.0N.Theaccelerationofthecartis

a) 0.070m/s2

b)1.5m/s2

c)7.5m/s2

d)15m/s2

e)30m/s2

4.Susanpushesagainsta100kgrockwithaforceof5.0N,buttherockdoesn'tmove.

TheforcetherockexertsonSusanis

a)0N

b)5.0N

c)20N

d)1.0x102N

5.Supposethattheonlyforcesactingona12kgmassarethoseshowninthediagram.

Theaccelerationofthemassshownwouldbe

a)0.5m/s2[W]

b)2.0m/s2[W]

c)5.0m/s2[W]

d)8.0m/s2[W]e) 24m/s2[W]

6.Whatforcewouldcausea250kgmotorcycletohaveanaverageaccelerationof

2.20m/s2for3.50seconds?

a)550N

b)1110N

c)32.6N

d)317N

7.Asubmarineistravellingunderwaterataconstantvelocity.Whichdiagrambestrepresentstheforcesactingonthesubmarine?

a)b)c)

d)e)

8.A10kgmassisliftedsothatitriseswithanaccelerationof2.0m/s2.(g=10N/kg).

Thenetforceexertedupwardsis

a)10N

b)20N

c)1.0x102N

d)1.2x102N

e)2.0x102N

9.Acartweighing490Nispushedbyanetforceof50N.Theaccelerationofthecartis

a)1.0m/s2

b)10m/s2

c)100m/s2

d)1000m/s2

10.Whatisthetensionintheropeconnectingthe12kgandthe5.1kgmassesasshowninthediagram?Considerthefrictionalforcestobeminimal.

a)9.8N

b)35N

c)50N

d)69N

11.Astringwithamassoneachendhangsoverafrictionlesspegasshowninthediagram.

Theaccelerationofthesystemis

a)1.0m/s2

b)2.0m/s2

c)3.3m/s2

d)6.7m/s2

e)9.8m/s2

12.Forcesactontheobjectbelowasshowninthediagram.Findthenetforce.

13.Acertaincar,ofmass1500kg,experiencesanaverageairdragforceof820.Nasitmovesalongtheroad.Ifthiscarnowisacceleratedatasteadyrateof1.5m/s2,andtheairdragforceremainedthesame,whatforwardsforcemustbeapplied?

14.Acertainforceacceleratesa600kgobjectat5.2m/s2,ifthemassissuddenlydoubledbuttheforceremainsthesame,whatisthenewacceleration(inm/s2)?

15.Themotorofaboatexertsaforwardsforceof22000N,buta forceofwaterdragof875Nmustbeconsidered.Iftheboatacceleratesatarateof1.25m/s2,whatisit'smass?

16.Twofrictionlessboxes,AandBaretiedtogetherwithapieceofstring.BoxAhasamassof5.0kgandboxBhasamassof15.0kg.Aforceof50.0NpullsboxAwhichdragsboxBalongbehindit.

a)Whatistheaccelerationofthetwoboxestogether?

b)HowmuchforcedoesthestringbehindboxApullboxBwith?

c)Althougha50.0NforcepullsboxA,thenetforceonboxAismuchless.Whatisit?

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