The time which I used to finish this paper was _______

Physics Test 1 – Mechanics Ch. 6 Projectile

Motion

Name : ______________ Score : Time Limit : 1 Hour 15

Minutes

Give all answers correct to 3 signifcant figures. Useful formulae is given

on the last page.

Section A : Multiple-Choice Questions (9 marks)

1.Which of the following descriptions of moving objects accurately

portray a projectile?

A. An object which is moving through the air and not touching any surface

B. Any object upon which air resistance is negligible

C. A falling feather D. A falling feather in a falling vacuum

chamber.

2.A rocket is fired at . If the initial horizontal velocity is 326 m/s,

what is the initial vertical velocity?

A. 188 m/s B. 380 m/s C. 330 m/s D. 250 m/s

3. A golfer drives her golf ball from the tee down the fairway in a high arcing

shot. When the ball is at the highest point of its flight :

A. v = a = 0 B. horizontal velocity and vertical velocity are both zero

C. horizontal velocity is non-zero and vertical velocity is zero

D. v is non-zero and the acceleration is zero

4. A soccer ball is kicked at a angle to the horizontal. It has an initial velocity

of 8 m/s. What is the vertical velocity of the ball as it hits the ground?

A. 8 m/s B. –6.6 m/s C. –8 m/s D. Cannot be

determined

5. Identical guns fire identical bullets horizontally at the same speed from the

same height above level planes, one on the Earth and the other on the Moon.

Which of the following three statements is/are true?

(1) The horizontal distance traveled by the bullet is greater for the Moon.

(2) The flight time is less for the bullet on the Earth.

(3) The velocity of the bullets at impact are the same.

A. I and II only B. II and III only C. I, II, and III D.

III only

1

6. A projectile has an initial velocity at an angle to the horizontal. It reaches

the highest point P of its trajectory in a time T after launch. The highest point is a vertical distance and a horizontal distance d from the firing piont. The speed

of the projectile at point P is v. Which of the follow are incorrect?

A. B. C. D.

7. What is the relationship between maximum range and maximum height for projectile motion? = ?

A. B. C. D.

8. A ball is projected with vertical velocity ‘u’ with an angle to the horizontal.

After what time (t) will the initial velocity be perpendicular with the instantaneous

velocity?

A. B. C. D.

9. The motion of a projectile is described by the equation . Which of the

following describes the range of the projectile?

A. B. C. D.

Section B : General Questions (47 marks)

10. Two boys stand on the balcony of their house, which is 3.29-meters above

surface level. They launch a rock upwards with velocity of 45.2 m/s N E. The

balloon lands in a duck pond shown below.

2

a)Determine the horizontal distance from launch location to landing

location.

b) It is given that the horizontal distance from the edge of the

balcony to point P is 205 m. Determine whether the weird / tall / fat

duck will be hit by the rock.

3

c)The duck falls after 1 second of impact with the rock.. The rock sinks

to the bottom of the pond with constant velocity of 1 m/s. Given that

the pond water provides a buoyancy force of 20N, calculate the

average force acting on the duck.

(6 marks)

11. An accident occurred on a bridge crossing a flat valley. A driver drove his

truck through a weak fence and landed in a pile of hay. Police inspection revealed

the following information : (6 marks)

-Magnitude of displacement from the edge of bridge to the point of collision with

hay = 42.90 m

-Angle of depression from the edge of bridge to the point of collision with hay =

a)If the force of impact with the fence was negligible, determine the

velocity of the truck before it fell down the bridge.

b) The driver was in a 29.0 m/s speed zone. Determine the amount by

which the driver was exceeding the speed limit at the time of the

accident.

c)Describe and explain the effect on the force acting upon the truck

and the driver during the collision with hay, if the hay was replaced

with barren surface of stone.

________________________________________________________

________________________________________________________12. A car is parked on a cliff overlooking the sea. The cliff is inclined at an angle

of below the horizontal. The negligent driver leaves the car in neutral and it

4

begins rolling from rest towards the edge.

a)The car moves a vertical distance of 26.2 m as it approaches the

edge of the cliff before plunging into the ocean below. Calculate its

velocity before it plunges down the cliff. (Hint : Energy is conserved)

5

b) The cliff is 42.2m above the sea. Find the

time it takes the car to drop to the water

below the cliff’s edge.

c)Describe the changes to horizontal range and final velocity in the

following situations :

(i)The angle of depression of the cliff increases, yet the horizontal

distance between the car’s original position and the cliff’s edge

remains the same

(ii) The cliff ends with a curved ramp going upwards

(iii) The mass of the car increases

(6 marks)

13. Li Ping Phar, the famous Chinese ski jumper, leaves the ramp at an angle of

35° in the Winter Olympics 2010 Ski-Jump Finals Event. He is the last athlete to

make the jump. The current rankings are shown below.

1st Finnast First (New World

Record !)

125 m

2nd Dunko Dostrich 118 m

3rd Thistle Thrice 116.5 m

4th Forn Fidalski 114 m

In this event, competitors land on a surface which is at the same height as the top

of the ramp.

a) Li wants to win at least a bronze medal. Determine the velocity before leaving

the ramp required if he needs to achieve at least 117 m of horizontal distance

b) Finnast First broke the world record by reaching a horizontal distance of 125

m. How much longer or shorter is Finnast’s time of flight different from Li’s time

of flight calculated in (a) ?

6

c) Lucy Fells holds last place in the event, after Li has completed his jump. A

speedometer shows that her velocity before she leaves the ramp is 17.2 m/s.

Determine the horizontal distance travelled by her.

*13d) The following diagram depicts the ski-ramp used in the event.

Assume that the bottom of the ramp is in the shape of a semi-circle with radius 2

metres.

(i)Finnast First has a mass of approximately 50 kg. If the normal force

acting upon Finnast’s body at the bottom of the ramp is 40092 N,

calculate Finnast’s velocity at the bottom of the ramp.

(ii) Height “H” represents the difference in height of the starting point

and the point where athletes leave the ramp. The starting point is

where athletes accelerate from rest. Determine the height of the

ramp from the starting point to the bottom of the ramp.

(Total : 13 marks)

14. Mr. P&D takes his three children to the park for some summertime recreation.

Andy and Danny are enjoying swinging and jumping. On one jump, Andy leaves

the swing at a 30° angle to the horizontal with a speed of 2.2 m/s. He lands on the

ground a horizontal distance of 1.09 m from the launch location.

7

a)Andy’s launch location was not at the same vertical height as the

landing location. Determine the vertical height (relative to the

landing location) from which Andy jumps from the swing.

b) Andy just flies over Peter’s head after 0.112 seconds from his

launch. Determine Peter’s height in cm.

(5 marks)

15. How can two projectiles launched with the same speed but at different angles

have the same range?

_______________________________________________________

__________________________________________________(2

marks)

16. You are given the following apparatus :

Crossbow with adjustable base Bean bags of different sizes C-clamp

Long meter rule 180-degree Protractor

It is known that the crossbow can shoot arrows with the same velocity for each

shot.

a)Describe an experiment to be carried out in a labarotory to

determine the angle to the horizontal which can achieve maximum

range for any projectile. (5 marks)

________________________________________________________

________________________________________________________

________________________________________________________

________________________________________________________

________________________________________________________b) Prove mathematically that, in the absence of air resistance, the

maximum range of any projectile is achieved when it is launched at

8

45° to the horizontal. (Hint : Given ) (4 marks)

Section D : Data-Response Questions (14 marks)

9

Juggling – A Stunt which Involes Projectile Physics Figure 1 shows a picture of a wooden juggling club. The mass of a juggling club is not evenly distributed between about the length of the club. There is more wood present near the (a), thus shifting the center of mass towards the (a) of the club. When a club is juggled, it rotates about its (b) as it travels through the air. The three boxes on the club indicate three positions on the club. The center box (not labeled) is the center of mass of the club.

1. Which of the following is closest to the vertical position of the head of the club

at 2.0 seconds?

A. 41 cm B. 1.09 m C. 0.132 km D. 2380 mm

2. What is the height of the handle of the club when it is at a horizontal position of

95 cm?

A. 30 cm B. 0.098 m C. 1530 mm D. 0.165 km

3. What is the height of the center of mass of the club when it is at a horizontal

position of 165 cm?

A. 0.90 m B. 148 cm C. 0.152 km D. 2520 mm

10

A video of a juggled club was taken and then analyzed to produce the graph shown in Figure 2.

The motion of the club through the air began approximately (c) seconds into the video. As shown on the graph, the club was released from a height of (d) metres above the ground. The horizontal and the vertical position of the three marked points are shown as a function of time. X represents the horizontal position while Y represents the vertical position. The zero position for the (e) motion is the ground.

4. Which part of the club – head or handle – is furthest (horizontally) from the

starting point and by how much at a time of 2.1 seconds?

A. The handle is furthest by 10 cm. B. The handle is furthest by 29 cm.

C. The handle is furthest by 34 cm. D. The head is furthest by 40 cm

5. Which of the following accurately depicts the state of the juggling club at t =

2.6 seconds?

6. State the times when the club is oriented as shown at the right.

T = ______________ (seconds)7. The diagram at the right shows two different orientations for the club. State a

possible time period in which the club rotates between these two orientations. (2

marks)

Starting time = ______________

(seconds)

Finish time = ______________

(seconds)8. Fill in the blanks in the passage below : (2 marks

if all correct)

(a)_______________ (refer to figure 1)

(b)_______________ (c) _______________

11

(d)_______________ (e) _______________

9. With reference to the provided data from the graph, estimate the initial velocity

of the juggling club when it was projected upwards at the start. Include both

magnitude and direction. Use the data of the centre of mass of the juggling club

to represent the projectile motion of the entire club.(4 marks)

Formulae :

PE = mgh KE =

12