almalki (aa79893) – assignment4 – kumar – (1824251) 1

This print-out should have 38 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering.

001 (part 1 of 3) 10.0 points Aparticle moves in the xy plane with constant acceleration. At time zero, the particle is at x = 7.5 m, y = 3.5 m, and has velocity ~vo = (5.5 m/s) ı̂ + (−1.5 m/s) ̂ . The acceleration is given by ~a = (8 m/s2) ı̂+ (8.5 m/s2) ̂ . What is the x component of velocity after

2 s? Answer in units of m/s.

002 (part 2 of 3) 10.0 points What is the y component of velocity after 2 s? Answer in units of m/s.

003 (part 3 of 3) 10.0 points What is the magnitude of the displacement from the origin (x = 0 m, y = 0 m) after 2 s? Answer in units of m.

004 (part 1 of 4) 10.0 points A plane is flying horizontally with speed 169 m/s at a height 4160 m above the ground, when a package is dropped from the plane. The acceleration of gravity is 9.8 m/s2 . Neglecting air resistance, when the package

hits the ground, the plane will be

1. behind the package.

2. ahead of the package.

3. directly above the package.

005 (part 2 of 4) 10.0 points What is the horizontal distance from the re- lease point to the impact point? Answer in units of m.

006 (part 3 of 4) 10.0 points A second package is thrown downward from the plane with a vertical speed v1 = 52 m/s. What is the magnitude of the total velocity

of the package at the moment it is thrown as seen by an observer on the ground?

Answer in units of m/s.

007 (part 4 of 4) 10.0 points What horizontal distance is traveled by this package? Answer in units of m.

008 10.0 points Assume: A 78 g basketball is launched at an angle of 42.1◦ and a distance of 14.9 m from the basketball goal. The ball is released at the same height (ten feet) as the basketball goal’s height. A basketball player tries to make a long

jump-shot as described above. The acceleration of gravity is 9.8 m/s2 . What speed must the player give the ball? Answer in units of m/s.

009 10.0 points A 0.33 kg rock is projected from the edge of the top of a building with an initial velocity of 7.13 m/s at an angle 38◦ above the horizontal. Due to gravity, the rock strikes the ground at a horizontal distance of 11.7 m from the base of the building.

B u il d in g

11.7 m

38 ◦7.

13 m /s

h

How tall is the building? Assume the ground is level and that the side of the build- ing is vertical. The acceleration of gravity is 9.8 m/s2 . Answer in units of m.

010 10.0 points A boat moves through the water of a river at 6.62 m/s relative to the water, regardless of

almalki (aa79893) – assignment4 – kumar – (1824251) 2

the boat’s direction. If the current is flowing at 5.75 m/s, how

long does it take the boat to complete a trip consisting of a 235 m displacement down- stream followed by a 149 m displacement up- stream? Answer in units of s.

011 (part 1 of 3) 10.0 points Two cars approach each other; both cars are moving westward, one at 83 km/h, the other at 63 km/h. What is the magnitude of the velocity of the

first car relative to (in the frame of reference of) the second car? Answer in units of km/h.

012 (part 2 of 3) 10.0 points What is the direction of the resultant veloc- ity?

1. Eastward

2. Unable to determine.

3. Westward

013 (part 3 of 3) 10.0 points After they pass, how will their relative veloc- ity change?

1. Unable to determine

2. Greater than before

3. Less than before

4. No change

014 (part 1 of 2) 10.0 points A camel sets out to cross the desert, which is 35.5 km wide in the north-south direc- tion. The camel walks at the uniform speed 4.53 km/hr along a straight line in the direc- tion 42.2◦ north of East (only the camel knows why he chose that particular direction).

θ

W E

N

S How long will it take the camel to cross the

desert? Answer in units of hr.

015 (part 2 of 2) 10.0 points Calculate the camel’s eastward displacement while he crosses the desert. Answer in units of km.

016 (part 1 of 2) 10.0 points A truck travels beneath an airplane that is moving 100 km/h at an angle of 55◦ to the ground. How fast must the truck travel to stay be-

neath the airplane? Answer in units of km/h.

017 (part 2 of 2) 10.0 points What is the magnitude of the vertical compo- nent of the velocity of the plane? Answer in units of km/h.

018 (part 1 of 2) 10.0 points A superhero flies 310 m from the top of a tall building at an angle of 30 ◦ below the horizontal. What is the horizontal component of the

superhero’s displacement? Draw the vectors to scale on a graph to determine the answer. Answer in units of m. Your answer must

be within ± 5.0%

019 (part 2 of 2) 10.0 points What is the vertical component of the super- hero’s displacement? Answer in units of m. Your answer must

be within ± 5.0%

020 (part 1 of 4) 10.0 points A shopper pushing a cart through a store

moves 30.0 m south down one aisle, then makes a 90◦ turn and moves 15.0 m. He

almalki (aa79893) – assignment4 – kumar – (1824251) 3

then makes another 90◦ turn and moves 19.0 m. What is the magnitude of the smallest pos-

sible displacement the shopper could have? You are not given the direction moved after any of the 90◦ turns, so there could be more than one answer. Answer in units of m.

021 (part 2 of 4) 10.0 points At how many degrees from due south is this displacement? Answer in units of ◦.

022 (part 3 of 4) 10.0 points What is the magnitude of the largest possible displacement the shopper could have? Answer in units of m.

023 (part 4 of 4) 10.0 points At how many degrees from due south is this displacement? Answer in units of ◦.

024 10.0 points The eye of a hurricane passes over Grand Bahama Island. It is moving in a direction 64.0◦ north of west with a speed of 49.7 km/h. Exactly 3.11 hours later, the course of the hurricane shifts due north, and its speed slows to 28.6 km/h, as shown. How far from Grand Bahama is the hurri-

cane 4.54 h after it passes over the island? Answer in units of km.

025 10.0 points A person walks 35 m East and then walks 36 m at an angle 40◦ North of East. What is the magnitude of the total dis-

placement? Answer in units of m.

026 (part 1 of 2) 10.0 points Instructions for finding a buried treasure in- clude the following: Go 527.9 paces at 298◦, turn to 115◦ and walk 251 paces, then travel 370 paces at 282◦. Find the magnitude of the resultant dis-

placement from the starting point.

Answer in units of paces.

027 (part 2 of 2) 10.0 points What is the direction of the resultant displace- ment? Use counterclockwise from due East as the positive angular direction, between the limits of −180◦ and +180◦. Answer in units of ◦.

028 (part 1 of 2) 10.0 points

Consider four vectors ~F1, ~F2, ~F3, and ~F4 with magnitudes F1 = 53 N, F2 = 21 N, F3 = 24 N, and F4 = 56 N, θ1 = 120

◦, θ2 = −140 ◦,

θ3 = 39 ◦, and θ4 = −51

◦, measured from the positive x axis with counterclockwise positive. What is the magnitude of the resultant vec-

tor ~F = ~F1 + ~F2 + ~F3 + ~F4? Answer in units of N.

029 (part 2 of 2) 10.0 points What is the direction of this resultant vec- tor ~F , within the limits of −180◦ and 180◦ as measured from the positive x axis with coun- terclockwise positive ? Answer in units of ◦.

030 (part 1 of 6) 10.0 points Find the magnitude and direction of the vec- tor sum ~R1 where ~R1 = ~A + ~B. The vector ~A = 10.8 m at an angle 180◦ from the positive horizontal axis, and ~B = 19.2 m at an angle 44◦ from the positive horizontal axis. Answer in units of m.

031 (part 2 of 6) 10.0 points At what angle (between −180◦ and 180◦ with 0◦ the positive x axis and counterclockwise positive) is the vector sum? Answer in units of ◦.

032 (part 3 of 6) 10.0 points What is the magnitude of the vector difference ~A− ~B? Answer in units of m.

033 (part 4 of 6) 10.0 points At what angle (between −180◦ and 180◦ with 0◦ the positive x axis) is the direction of this

almalki (aa79893) – assignment4 – kumar – (1824251) 4

resulting vector? Answer in units of ◦.

034 (part 5 of 6) 10.0 points What is the magnitude of the vector difference ~B − ~A? Answer in units of m.

035 (part 6 of 6) 10.0 points At what angle (between −180◦ and 180◦ with 0◦ the positive x axis) is the direction of this resulting vector? Answer in units of ◦.

036 (part 1 of 3) 10.0 points Neglect: Air friction. Your teacher tosses a basketball. The ball

gets through the hoop (lucky shot).

b

2 .4 8 4 m

3 .0 4 8 m

18 m /s

49 ◦

b

b

b

b

b

b

b

b b

b b b

b b b b b

b b

b

Figure: Not drawn to scale. How long does it take the ball to reach its

maximum height? Answer in units of s.

037 (part 2 of 3) 10.0 points How long does it take the ball to reach the hoop? Answer in units of s.

038 (part 3 of 3) 10.0 points What is the horizontal length ℓ of the shot? Answer in units of m.