105old Exam2 Solutions

7/17/2019 105old Exam2 Solutions

http://slidepdf.com/reader/full/105old-exam2-solutions 1/6

g.i.

iti

.ii

i

'"

| . .

,l

.

,j

:

.1

: . "

1

f'

:l

d.,,

:i

q:

-i

i-

g:

.r .

j

$:J.

$l

i.

:.

li'.



1 .

This is to

identify the exam version you

have

-

IMPORTANT

Mark the A

2.

This is to identify the

exam version you

have

-

IMPORTANT

Mark the B

3 .

n

(

If the

only

forces

acting

on

a 2.0-kg

massare F,

=

(3i

-

8j) N and

F,

=

(5i

+

3j) N, what is

the mamitude of the acceleration

f the

mass?

*s) '' {'1-i

. 1 .5

m/S-

iat

=l'?

=

tn

n(5.

4.

^

H

l l

h

A block is

pushed up a frictionless

30' incline by an

applied

force as

shown. If f

=

25

N

and M

=

3.0 kg, what is

the magnitude

of the resulting total acceleration

[we

have

vity, tool of the block?

3a

t.u

2d '

tr

a

a.

b.

c.

q .

e.

.,.tf

th1

,.;-7=,G

f / , ) rv/ s

4.6m/s2

J.5 m/

s -

2.9 rn/

s2

5.1

m/

S-

5 .

' t 1

\,

An astronaut

[m

=

81.6kg] lifts

off from planet Zuton

in a spaceship. The free-fall

accelerationn Zuton s 3.0m/s2 (down).At the momentof liftoff the accelerationf

h

Bzn

o*

=

h -

3 2 ,

t " -

I

Jr^,*

b .

c,

d.

the

spaceship is 0.50m/gf{gn).

\A4rat s

the magnitude

of

the force

of

the

spaceship on

the astronautl

I

l-C

nct

fdrp

€ : F

* . t r t ' Q

0.20 N

0.37 N

al

,_(

a ,

f

z



b .

1

7

The horizontal

surface

on

which

the objects

slide

s frictiorLless.f M

=

1.0kg and the

magnitude

of

the force

of the small block

on the large block

is

5.2 N, determine F.

:

f Zv

=74

'IVrre

b .

d.

e,

6.0N

&

.8N

4.1N

Z E

2n,W

=

(zn te

{ . s . 2

CI

r/

7.

c,

Two bodies,A

and B, collide as

shown in Figuresa and b below.

t o t

a t u

. t u

(a )

(b)

Which statement s true?

a. They exert

equal and opposite orces

on eachother

n

(a)

but not in

(b).

a,

They

exert equal and

opposite

orce

on each

other

n

(b)

but not in

(a).

I

They

erert equaland

opposite

orce

on

each

other

n both

(a)

and

(b).

9i

d. The

forcesare

equal and opposite o

eachother

n

(a),

but

only

the

components

of the forces

parallel to the velocitiesare

equal n

(b).

e. The

forcesare

equal

and

opposite n

(a),

but

only

the

componentsof

the forces

perpendicular to the velocities

are equal n

(b)

8.

0

Threeboxes

slide on a frictionlesshorizontal

surfacewhen pulled by a force of

magnitude F. When

we cornpare he tensions

I

and T, with the force F, we find ihat

a.

b .

'1-

- ' , t ' -

E

T t = F > T z

F > T r = T r .

L > 1 1 > 1 2 . V

F T 1 < 7 1 - T 2 .

c ,

)

e,

a



9.

.7

A roller-coaster

ar has a mass

of 500kg

when fully loaded with

passengers. he car

passes ver a hill

of radius 15 m, as

shown.

At the top of the hi1l, he car has a

speedof

(

a,

b .

7.0kN up

7.0kN down

2.8kN

down

a ' < - - \ ' \

<_rykNrd)

5.6kN down

L& na"( ;

. - L

t B ' n t

= z t g J

\t€

zc"

1*'n

Fo

=

n^:6

=

?2oo

0

t J [qztz^Lt3J,tu n,a,1

c.

d.

td.a

t4ztlr

10.

{

" l

1

a.

b .

:N

o .

ever).where

he same

at the top

at the bottom

l o f r r n r l t i o h t^_" __'- _ ' t t_

"

4n



1 1 .

c

An objectmoving along the :r axis s acted

upon by a force

F, that varies with

position

as

shown.

How much

work

is

done bv this force as he obiectmoves

rom

x = 2 r r . t o x = 8 r n ?

r,

(N)

",. . . . ' -* '7L

L)=

:

fin,

<r

*

?ol

x *

= ( , gz?=

4D'.

(

30'tt

J

a.

b.

@

d.

e.

- 1 0

T

+10

+30

-30

J

+40 T

1,2.

q

A 10-kg

block on a horizontal frictionless

surface s attached o a

llght

spring

(force

constant

=

1.2

kN/m). The block is initially at rest at its equilibrium

position

when a

force

(magnitude

P)

acting parallel to the

surface

s appl ied to the block, as shown.

When

the block is

8.0cm from the equilibrium

position,

t has a

speed

of 0.80m/s.

How much work is done

on the block by the force P as he block moves the 8.0 cm?

r(/et,

l*ts

&

,i)

=

lj,"p

r

I

u l *

tQ

+p

* Q

+Dp

I

=1'

0

a.

D .

d.

8 3 1

,

I

llro.

t

)

k x *



13.

E

a.

I

c.

d .

Carts A and B have equal masses nd travel

equal distances

D

on side-by-sidestraight

frlctionless

racks while a constant orce F

actson

A and a

constant

orce 2F actson

B.

Both

carts start

fuom

rest. The velocitiesvo and vu

of

the bodies at the end of distance

D

are related by

ft:

tr

*>

1,4)

E

2p

*>2rJ

v u = 2 v o ,

vA

=

2vB.

tu

=

1p

.,ro.

*.,

/a

-)

v

.-',1rr

-)

'r{

v

*r = '+ r/r

1.4.

?

A champion athlete

can produce one horsepower

(746

W) for a short period of time.

If

a athletewere to bicycle

[70-kg

combined athlete+ bike] to the summit of a 500m high

mountain while expending

power

at this rate,

she would

reachJhe

sumrnit

in ho,rv

a

any

seconds?

a. 1

1000

35000

L l + a 6

P

7

d.

105old Exam2 Solutions

Documents

Transcript of 105old Exam2 Solutions