FINAL EXAM

Question 1

The density of aluminum is 5.94×10^-3 Ib/cm what is the density in kilogram per cubic meter if 1 pound = 0.454 kg and 1 m = 100 cm

A)1.2310^3
B)2.7010^3
C)1.2310^6
D)2.7010^6
E)5.94*10^3

Answer 1

2.70*10^3

Question 2

An object moves along a straight line with a constant speed of V = 10+/-0.2 m/s for a period of time T = 3.2+/-.1 s what is the distance the object has traveled during this time

A)13.2+/-0.3
B)32+/-0.2
C)32+/-0.3
D)32+/-1.2
E)32+/-2

Answer 2

32+/-1.2

Question 3

If a=(1,2,-3) and b=(3,1,-2) what the angle between a and b in radians

A)0.32
B)0.67
C)0.92
D)1.57
E)3.14

Answer 3

0.67

Question 4

Two displacement vector a=10i -2j and b=5i +5j cube the time when A is perpendicular to b

A)2s
B)3s
C)4s
D)5s
E)6s

Answer 4

5s

Question 5

Compute the magnitude and angle with respect to the X axis for a velocity vector v=2i+5j

A)v=7 theta=0.4
B)v=7 theta=1.2
C)v= square root 29 theta=0.4
D)v=square root 29 theta=1.2
E)v=5 theta=1.2

Answer 5

V=square root 29 theta =1.2

Question 6

A particle move the accordingly to the equation X= 3t^2-5t+8 find the average velocity from T=0 to T=2 in the magnitude of the instantaneous velocity at T=2

A)vavf=1 v(t=2)=7
B)vavg=2.5 v(t=2)=7
C)vavg=-1 v(t=2)=3.5
D)vavg=5 v(t=2)=1
E)vavg =1 v(t=2)=1

Answer 6

A)vavf=1 v(t=2)=7

Question 7

An airplane touches the ground with an initial speed of 100 a D accelerates along the runway for 25 seconds until it stops. What is the airplane acceleration? What is the distance it travels during that time

A)a=-2.5 d=1500
B)a=-1.25 d=500
C)a=-4 d=1250
D)a=-5 d=2000
E )a=-3.25 d=1500

Answer 7

A=-4 d=1250

Question 8

a particle is projected froma horizontal plane on the ground with v=8square root 2 at some angle at the highest point its trajectory the magnitude of its velicity is found to be 8 at this time it horizontal distance is

A)6.5
B)3.2
C)5.0
D)9.8
E )13

Answer 8

6.5

Question 9

A tennis balls is thrown at 20 m/s at angle of 60 up from the horizontal how long would it take for the ball to travel a horizontal distance of 10 m how high abkve the launch point was the ball at that time

A)t=2h=20
B)t=1.5h=17.4
C)t=1.2h=13.7
D)t=1 h=12.4
E )t=0.5 h=9.7

Answer 9

T=1 h=12.4

Question 10

The moon travels at a speed of 2300 miles/hour around the earth the distance between the moon and the earth is 238900 miles what is the magnitude of the centripetal acceleration on the moon 1 mile=1609 m 1 hour=3600s

A)2.21410^1
B)1.709x10^0
C)7.23510^-1
D)4.35910^-2
E )2.74910^-3

Answer 10

2.749*10^-3

Question 11

A car travels north with an increasing speed the net force of the car is

A)east
B)west
C)north
D)south
E )zero

Answer 11

North

Question 12

An 80 KG man stands on a bathroom scale in an elevator as the elevator starts moving the scale read 600 N the acceleration of the elevator is

A)4.9 upward
B)4.9 downward
C)2.3 upward
D)2.3 downward
E )0

Answer 12

2.3 downward

Question 13

A two KG block is placed against a rough wall and is held stationary by a force of 16n applied at 60° angle shown in the drawing what is the magnitude of the friction force?

A)5.74
B)8
C)11.6
D)16
E )19.6

Answer 13

5.74

Question 14

Two blocks are connected by a string that passes over a fictionist pulley and M1=2 the magnitude of the acceleration block is

A)g/4
B)g/3
C)g/2
D)2g/3
E )g

Answer 14

G/3

Question 15

One end of a 1 m long string is fixed. The other end is attached to a two KG stone. The stone swings in a vertical circle pass it with 45° point at 4 m/s the tension of the force of the string at this point is.

A)0
B)19.6
C)32.0
D)45.9
E )52.3

Answer 15

45.9

Question 16

One particle has a mass M and a second particle has a mass of 2M the second particle is moving with a speed of V and the first particle is moving with the speed of 2V how do their kinetic energies compare?

A)k1=k2
B)k1=k2/2
C)k1=2k2
D)k1=k2/4
E )k1=4k2

Answer 16

K1=2k2

Question 17

A box with mass m slides up a frictionless incline plane it starts with an initial velocity the incline plane has an angle with respect to the ground what is the maximum height the box can reach on the incline plane?

A)v0^2/(2g)
B)v0^2/g
C)2v0cos a/g
D)v0^2/(mg)
E )v0^2sina/g

Answer 17

V0^2/2g

Question 18

In elevator lifts 10 persons with a total weight of 8000 and going up with a constant velocity of v= 1 what is the power of the elevator?

A)8000
B)16000
C)32000
D)78400
E )96000

Answer 18

8000

Question 19

An object with mass M is hooked by spring the spring coefficient is K it’s released from point a where the spring is added its natural length the object is released at rest from .8 how long does the spring stretch when the object reaches lowest point?

A)2mg/k
B)squareroot 2mg/k
C)mg/k
D)mg/2k
E )squareroot mg/2k

Answer 19

2mg/k

Question 20

A box with mass M is released from rust from a compressed spring on a frictionless surface with a height, H from the ground. The spring has a spring, constant K and was initially compressed by a distance of X from its natural length before the release. Find the boxes, velocity magnitude when it falls off the table and hits the ground

a) v=square root 2gh
B)v=xsquare root k divided by m
C)v=xsquare root k divided by 2m
D)v=square root go plus k divided by m times x^2
E)v=square root 2gh plus kdivjded by m times. ^2

Answer 20

E)v=square root 2gh plus kdivjded by m times. ^2

Question 21

Which of the following has the largest magnitude of momentum?
A) M equals one KG with V equals 1.5
B) M equals two KG with V equals 0.5
C) M equals 0.5 KG with V equals two
D) M equals 1.5 KG with V equals 0.5
E) M equals one KG with V equals 1 m/s i plus 0.5 m/scj

Answer 21

A) M equals one KG with V equals 1.5

Question 22

An object with mass M equals five KG moves with an initial velocity of V equals -2 m/s after a bounces back from the wall. It has a velocity of V equals 0.3 m/s neglecting the gravitational force here what is the impulse the wall excerpts on the object when they interact.
A) j=1.5
B) J equals 11.5
C) J equals -11.5
D) J equals 10
E) J equals -10

Answer 22

B) J equals 11.5

Question 23

A ball of mass M equals 10 KG is moving with a velocity of V equals one is split into two parts one piece with mass M equals three KG move with a velocity of V equals -2. What is the velocity of the other piece?

a) V equals -2.8
B) V equals -1.5
C) V equals 2.3
D) V equals 3.4
E) V equals 4.2

Answer 23

C) V equals 2.3

Question 24

A great white shark of mass M coasting through the water in a nearly frictionless way at speed and golf, La tuna of mass M equals M divided by, three traveling the same distance at the speed where V2 is less than version one swallowing it in one bite what is the speed after it’s tasty meal

A) V equals V2
B) V equals V one
C) V equals (2V one plus V2) divided by three
D ) V equals( 3V1plus V2) divided by four
E) V equals(2V one plus 3V2) divided by five

Answer 24

D ) V equals( 3V1plus V2) divided by four

Question 25

Two balls collide with each other elastically one has a mass M1 and moves with a velocity V1 equals two ball two has mass two equals 2M and moves with a velocity V2 equals negative V what are the velocities of the two balls after the collision? A) V one equals negative V ; V2 equals 2V B) V one equals negative -2V ; V2 equals V C) V one equals equals negative V divided by two; V2 equals V D) V one equals negative V; V2 equals V divided by two E) V one equals -5÷3; V2 equals V divided by three

Answer 25

B) V one equals negative -2V ; V2 equals V

Question 26

Five balls with equal mass form a W in the XY plane their corresponding(-2,1),(-1,-1),(0,0.8),(1,-1),(2,1) find the center of the mass for the system A) (0,-0.24) B)(0,0) C)(0,0.16) D)(0,0.4) E)(0.2,0.4)

Answer 26

C)(0,0.16)

Question 27

A car accelerates from rest to V equals 30 m/s in 10 seconds. The tires have a radius of R equals 0.5 m. What is the angular acceleration of the tires? a) a=3 B)a=6 C)a=9 D)a=12 E)a=18

Answer 27

B)a=6

Question 28

A centerifuge in a medical laboratory rotates at an angular speed of 5400 RPM one switched off it rotates 100 revolutions before coming to arrest find the magnitude of the constant angular acceleration of centerifuge Wallace slows down to a stop A) a= 0 B)a=18 pi C)a=36 pi D)a=54pi E)a=81pi

Answer 28

E)a=81pi

Question 29

A turntable is initially at rest. It starts rotating with a constant angular acceleration of a equals 3 for 5 seconds and then starts to slow down with an angular acceleration of a equals negative one until it stops. How many radiance does the turntable rotate for the entire process A ) theta =50 B) theta =75 C) theta =100 D) theta =120 E) theta =150

Answer 29

E) theta =150

Question 30

A ball held by a string, as shown, is released from the horizontal position at a downward tangential speed of 5 m/s. The string has length L. What is the ball’s speed when it reaches to the bottom of the circle? (Hint: The ball can be treated as a point particle.)

Answer 30

vf=square root 2gL +v^2 or 5 sqare root 2gL

Question 31

A spring-powered gun has a spring constant of 20 N/m. The spring is compressed by 20 cm and a 10 g projectile is placed in the gun. The spring then is released. Determine the velocity of the projectile when it leaves the spring.

Answer 31

v= sqaure root R/M times x v=8.9

Question 32

Calculate the final speed of a 120 kg football player, who is initially running at 8.00 m/s, after he collides head-on with a padded goalpost and experiences a backward force of 1.5*10^4 N for 5*10^-2 s.

Answer 32

1.75

Question 33

4. A 2000 kg car travels at 10 m/s North and collides with a 2500 kg car traveling EAST. The collision is completely inelastic and they together travel North-East after the collision. What is the initial velocity of the East bound car?

Answer 33

M1/M2 times v1

Question 34

(A) v =1.52m/s (B) v =2.54m/s 5. A flywheel slows from 2200 to 300 rev/min while rotating through 100 revolutions. What is the angular acceleration of the flywheel during that time?

Answer 34

-4.08

Question 35

6. A disk of mass 2 kg and radius of 100 cm is rotating at 15.0 rad/s. It is brought to rest in 5.0 s (E) v =5.02m/s I = 1 at a constant angular acceleration. The moment of inertia of the disk is . What is 2 mr2 the magnitude of the torque needed to bring the disk to rest?

Answer 35

0.03

Question 36

. A pendulum consists of a massless string with length L = 2 m with a solid sphere at one end with mass 1 kg and radius 0.75 m. If the pendulum is released from rest at an angle of 50o, what is the angular velocity at the lowest point

Answer 36

1/2mv^2(1+2/5)=mgL(1-costheta)

Question 37

8. A bowling ball of mass 6.5 kg and radius of 0.09 m is rolling without sliding along level ground. Its center-of-mass speed is 1.5 m/s. Determine its total kinetic energy.

Answer 37

K=1/2mv^2(1+2/5)

Question 38

A bee of mass 0.1 g is moving at a speed of 1 m/s when it collides and sticks to a uniform solid cylinder. The cylinder has a mass 0.2 kg, a radius 15 cm, and is initially at rest. It is free to rotate about its axis through its center and is perpendicular to the page. What is the angular velocity of the bee after the collision?

Answer 38

(0.0001)/(0.0001+0.2) times (1/0.15)times 1

Question 39

An 10 kg, 8 m long, ladder is resting against a frictionless wall as shown. The ground is rough. What is the magnitude of the (net) force at point P?

Answer 39

F=mg square root (1/4 tan^2theta plus 1)

Question 40

A football is kicked at 24 m/s at an angle of 50° above the horizontal. How long will it take the football to travel 12 meters horizontally, and how high above the launch point is the ball at that moment? A) t = 2.5 s, h = 21.7 m B) t = 1.8 s, h = 19.4 m C) t = 1.2 s, h = 12.5 m D) t = 0. 7s, h = 10.47 m E) t = 0.5 s, h = 5.1 m

Answer 40

D t = 0. 7s, h = 10.47 m