Question

In the figure, a washer rotates on a string (string not shown) in the circular path shown in red. Which arrow best describes the velocity vector at that instant in time?


(Points : 1)
arrow A

arrow B

arrow C

arrow D

Answer 1

the velocity arrow is tangential to the circle

Answer 2

So which arrow is it?

Answer 3

Well judging from the circle pointing left, we can assuming the washer is travelling counterclockwise around the circle...so at the top...it would be going (in what arrowed direction) to continue travelling in that direction?

Answer 4

Yes

Answer 5

there was a question at the end :)

Answer 6

Sorry my laptop is dying so i'am charging it now but I would think south east? or am i ?wrong

Answer 7

Not quite....

so look at it like this

Answer 8

OH THAT MAKES SENSE NOW!

Answer 9

okay so it would be arrow b?

Answer 10

Indeed^ :)

Answer 11

Thanks I need more help with more questions i would love your help!

Answer 12

If I can :)

Answer 13

. A runner moving at a speed of 10.0 m/s rounds a bend with a 25.0 m radius. What is the centripetal acceleration that she experiences?
(Points : 1)
0.40 m/s2

62.5 m/s2

2.50 m/s2

4.00 m/s2

Answer 14

Hint...the centripetal acceleration is expressed as

\[\large A_c = \frac{v^2}{r}\]

Answer 15

So its Ac=10^2/25 ?

Answer 16

mmhmm...which can be simplified to...:)

Answer 17

4?

Answer 18

aka 4.00

Answer 19

???

Answer 20

Oops sorry yes 4 ^_^ lol

Answer 21

Thanks!

Answer 22

no problem :)

Answer 23

. A 70.0 kg runner moving at a speed of 10.0 m/s rounds a bend with a 25.0 m radius. What is the centripetal force that she experiences?
(Points : 1)
175 N

280 N

28.0 N

4375 N

Answer 24

Sorry I need a lot of help! Cyber school the worst !

Answer 25

No its okay :)

and entripetal force is very similar...we just have

\[\large F_c = \frac{mv^2}{r}\]

Answer 26

Where are these equations my physics teacher never showed us them

Answer 27

Lol well Ive taken 3 physics courses since I started college and I learned this in first semester...kinematics

Answer 28

and so it would be Fc=70.0^2/25 ?

Answer 29

Not quite....you forgot the v :)

unless that decimal is not supposed to be there

regardless...you square the velocity first...then multiply by the mass etc...

Answer 30

Can you show me how ? write the equation with the proper numbers in it? its
. A 70.0 kg runner moving at a speed of 10.0 m/s rounds a bend with a 25.0 m radius. What is the centripetal force that she experiences?
(Points : 1)
175 N

280 N

28.0 N

4375 N

Answer 31

So we have

\[\large F_c = \frac{mv^2}{r}\]

Plug in what numbers you have

\[\large F_c = \frac{(70)(10)^2}{25}\]

Remember the orderof operations....exponents first...so

\[\large F_c = \frac{(70)(100)}{25}\]
\[\large F_c = \frac{700}{25}\]
\[\large F_c = ?\]

Answer 32

28!

Answer 33

Indeed^ :)

Answer 34

28 newtons!

Answer 35

Lol yes correct :)

Answer 36

I got a whole lot more is it fine you can still help me? honestly this is the best help ive have gotten with physics is so long! I appreciate it

Answer 37

:D

Answer 38

Lol I'm happy its making sense hun :) and sure I'm just studying for a calc test so I'm on here anyways lol :P

Answer 39

What causes the centripetal acceleration of an electron in a hydrogen atom?
(Points : 1)
electrical attraction

gravity

friction

tension
SO>

Answer 40

I believe it would be tension?

Answer 41

Hmm, I'm actually not too sure on this one...not sure why it would be tension however, I would go to electrical attraction before that

Answer 42

I read it wrong! ugh you are right

Answer 43

:D

Answer 44

^_^

Answer 45

Which of the following terms might a jet pilot use to describe a force that presses him against his seat during a high-speed turn?
(Points : 1)
radial force

centrifugal force

tangential force

perpendicular force

Answer 46

You know this one :)

Answer 47

This is really confusing

Answer 48

Would it be c or d?

Answer 49

Im wrong ?

Answer 50

Sorry I actually read this wrong...the answer wording is terrible lol

Well b is not actually real. So it cannot be that
It cant be radial because that would follow the circle..
Tangential? Idk perhaps
Perpendicular force? dont think so...it would mean you would go foward if the plane is going left or right

I'd go with tangential maybe...sorry not too sure here

Answer 51

well i got a 3 out of 6 thanks again!

Answer 52

Does it tell you which is incorrect?

Answer 53

yes

Answer 54

it was the last one

Answer 55

Which ones did *we* get wrong?

Answer 56

The last one thats all & i just got the wrong 28 and i did one on my own but its okay i got an 80%

Answer 57

Oh okay...sorry i just wasnt too sure on that last one :(

Answer 58

. A point on the tread of a tire with a radius of 0.50 m rotates one-quarter turn, which is /2 radians. What is the linear distance of the displacement?
(Points : 1)
0.32 m

0.45 m

0.79 m

1.6 m

Answer 59

And thats completely fine!