Mechanics 1 potiential energy

**2** A block of mass http://www.thestudentroom.co.uk/late...f9149dccc8.png is placed on a rough horizontal table. A string attached to the block runs horizontally to the edge of the table, passes round a smooth peg, and supports a sphere of mass http://www.thestudentroom.co.uk/late...7e255f8d10.png attached to its other end. The motion of the block on the table is resisted by a frictional force of magnitude http://www.thestudentroom.co.uk/late...c247ea634e.png, where http://www.thestudentroom.co.uk/late...2c945574ac.png. The system is initally at rest.

a) Show that when the block and the sphere have each moved a distance http://www.thestudentroom.co.uk/late...14fb188cc8.png, their common speed is given by http://www.thestudentroom.co.uk/late...4128cd03cd.png

b) Show that the total energy lost by the sphere as it falls through the distance http://www.thestudentroom.co.uk/late...14fb188cc8.png is http://www.thestudentroom.co.uk/late...e93949dc8b.png

c) Write down an expression for the energy gained by the block as it moves through the distance h use your answer to check the expression for the tension which you found in part (b)

**Answer **Now I can manage part a: http://www.thestudentroom.co.uk/late...54aa7ec3f3.png, so http://www.thestudentroom.co.uk/late...88ac14fb4e.png. This is easy enough to rearrange to make http://www.thestudentroom.co.uk/late...61c5687b27.png the subject and get the expression in part a).

this leads me to answer in part b

add fractions

http://www.thestudentroom.co.uk/late...cafc057bf1.png

http://www.thestudentroom.co.uk/late...a483793ef3.png

but i cant solve the part c can anyone help

Re: Mechanics 1 potiential energy

The problem you are refered to is included in the book Mechanics 1 by Douglas Quadling for IG students of grade 11 ,page 142 ex 9.

For the part c just remember that W= TXh where T is the tension of the string.This W is transfered to kinetic energy (1/2 )mv^2

Substitute v^2 in the above expression and part c is resolved

Minoas

Re: Mechanics 1 potiential energy

but it asks to verify T tension in the part c how to verify that? and what does W represent

[Solved] Re: Mechanics 1 potiential energy

[SOLVED] Re: Mechanics 1 potiential energy