Question

A few physics review questions! Please help quickly! Medal will be rewarded to best answer!
If you apply 1.0 N of force to lift an object with a single-fixed pulley, then what is the resistive force?

A man pulls a box with a rope parallel to the ground. He pulls the box 100.0 m and does 5,000 J of work. What was the mass of that box?

A man begins pushing a lawn mower across a lawn from a standing start. Which statement is true?
A. Man is decreasing kinetic energy (KE) of lawn mower.
B. KE of lawn mower is not changing.
C. Man is increasing KE of lawn mower.
D. Cannot tell

Answer 1

@petiteme

Answer 2

to the first one, either friction, gravity or both depending on how detailed you want to get

for the second, since no angle is involved, W=Force*distance

Answer 3

for the first option I have 0.5 N,1.0 N, 1.5 N,2.0 N

Answer 4

gotcha, should be 1.0 N then

Answer 5

cool

Answer 6

You got it :D

Answer 7

Sorry. I was doing something ^_^

Answer 8

for the second question it would be 5,000 divided by 100.0?

Answer 9

@petiteme

Answer 10

Work = force x distance

Answer 11

So is you divide work and distance, you'll just get force

Answer 12

if*

Answer 13

ok so 50 divided by 9.8 gives me mass?

Answer 14

5.1 approximately would be the mass? @petiteme

Answer 15

F = ma
m = F/a
So yeah :D

Answer 16

Good job! ^_^

Answer 17

awesome! onto the third question

Answer 18

@petiteme @MrDoe

Answer 19

The man is keeping the lawn mowers kinetic energy stable. Its not changing.

Answer 20

awesome! you're really a great help! I've got one last sheet of work and I'll be done just a couple more relatively simpler questions

Answer 21

Okies ^_^ You interact with me so that's great ^_^

Answer 22

Of the following machines, which is not related to the others? Screw, lamp, or lever?

A motorboat travels directly east. During its trip winds blow from directly north, south, and southwest. Which is true?
A. Only southwest wind does work
B. All winds do work
C. Only north wind does work
D. Only south wind does work.

If a runner has power output of 150 W over 10.05, then how much work does he do?

Which is a simple machine?
bicycle, steering wheel system on boat, car or ramp?

which machine is 2 inclined planes?
doorstop, ax, screw, ramp?

Answer 23

@petiteme

Answer 24

@petiteme

Answer 25

I guess only the southwest wind does work on the boat.

Answer 26

yep

Answer 27

second question I'm stuck on

Answer 28

I mean the first

Answer 29

@petiteme

Answer 30

Of the following machines, which is not related to the others? Screw, lamp, or lever?

Answer 31

yes would it be the lever?

Answer 32

and the runner question would be the last one giving me trouble

Answer 33

@petiteme

Answer 34

5 minutes left

Answer 35

sorry study sheet is online and timed :/

Answer 36

The first one is lamp :D

Answer 37

ok

Answer 38

I would say:

1N
Use E=dF
KE is basically movement

Answer 39

He got it ^_^ Lol @wolfe8 YOU STALKER :P

Answer 40

sorry meant to say screw ramp or lever for the first

Answer 41

k so the answer is 1 N?

Answer 42

@wolfe8 @petiteme

Answer 43

could you tell me the answers in order to see if what I have is correct?

Answer 44

Well no that I think about it, does the object move? If yes, then the resistive force must be less than the opposing force for it to move with the opposing direction.

Answer 45

I have ramp, A, ---, ramp, and ax

Answer 46

is that correct? well except the third :P

Answer 47

@wolfe8 @petiteme

Answer 48

For the 3rd one use W=Pt

Answer 49

^

Answer 50

so are the first two correct?

Answer 51

I think all of them are correct

Answer 52

yeahhhhhhhhh ^^

Answer 53

p times t??

Answer 54

please help me what the heck is p times t? output x time?

Answer 55

Pt=Power multiplied with time

Answer 56

ok and the first answer is ramp?

Answer 57

They're all right

Answer 58

ok thank you

Answer 59

^_^