Question

Find the coefficient of friction

Answer 1

F= uR

Answer 2

From X component we got
\[X: Fcos(25)-f=ma\]
From Y component we got
\[Y: R-18g=0\]
Agree?

Answer 3

yes

Answer 4

Wait Y component we got
\[Y: R+30\sin(25)-18g=0\]

Answer 5

just abput to say that :P

Answer 6

So from X
\[30\cos(25)-f=0.4(18) \\ \\ 30\cos(25)=\mu R+(7.2)\]
Then find R from Y, then substitute that R into this equation and you will find mu

Answer 7

thanksss!!

Answer 8

What you got for R?

Answer 9

0.122

Answer 10

That is \(\mu\), but you got it, great!

Answer 11

oh sorry yeh, thanks so much

Answer 12

also how do you know how long it takes to travel 50m? do you use suvat?

Answer 13

There are number of ways, that depends on whether they give you time, acceleration, initial velocity, final velocity etc, or you can use energy to calculate as well

Answer 14

ok, well s= 50 and u=0 and v=?? and a=0.4 and we want to find t

Answer 15

yay I got the answer :)

Answer 16

ok

Answer 17

could you help me with another q please?

Answer 18

I gotta go now, maybe unkle will help? ;)

Answer 19

well ok thakns