$6.$ A solid uniform disk $($mass mdisk $=0\mathrm{.}750$ kg$,$ radius R $=12\mathrm{.}0$ cm$)$ and a block $($mass mblock $=$

$0\mathrm{.}750$ kg$)$ are released at the same time at the top of the ramp $($h $=0\mathrm{.}500$ m$).$ The coefficient

of friction is the same for both $($ $=0\mathrm{.}25).$ The angle is $30$ and d$=1$ m$.$

Hint: is this friction static or kinetic?

a$)$ Calculate the speed of each object at the bottom of the ramp.

b$)$ Which object gets to the bottom first?

c$)$ If the block was sliding without friction, how would your answer to $($b$)$ change?

Explain, without doing any calculations.