Question

Friction?

Answer 1

if the final kinetic energy is 0 all of the inital kinetic energy must have been opposed by the friction

so initial kinetic energy = work done = your answer

same formula as before, 1/2 mv^2

Answer 2

still there?

Answer 3

here, sorry

Answer 4

20

Answer 5

**

Answer 6

good

I am going to ask for a second opinion about the sign convention b/c I think it should be -20 J but am not 100% sure @sillybilly123

Answer 7

Sure

Answer 8

@sillybilly123

Answer 9

yeah it's the negative option

cos the force and direction vectors point in opposite directions

good spot