I really need help with two physics questions, if anyone's willing to explain them and help. PLEASE!

A man uses a lever jack to lift a 2.00 × 10^3 kg car to change a tire. Each stroke of the jack lifts the car a distance of 5.00 × 10^(-3) m. The vertical displacement of the handle is 0.75 m for each stroke. How much total force does he use with each stroke of the jack?

A. 3.0 x 10^5 N
B. 2.9 x 10^6 N
C. 131 N
D. 19,600 N

Question

I really need help with two physics questions, if anyone's willing to explain them and help.  PLEASE!

A man uses a lever jack to lift a 2.00 × 10^3 kg car to change a tire. Each stroke of the jack lifts the car a distance of 5.00 × 10^(-3) m.  The vertical displacement of the handle is 0.75 m for each stroke.  How much total force does he use with each stroke of the jack? 

A. 3.0 x 10^5 N
B. 2.9 x 10^6 N
C. 131 N
D. 19,600 N

anonymous · Answer

Let force applied on jack be F, mass of car is m, vertical displacement of car with every stroke is $$\Delta x$$, length of handle is l.
Then work done on the jack = potential energy gained by car(by its upward progress)
so, $$F * l = m*g*\Delta x$$
Hence, $$F = m*g*\Delta x /l$$
this comes out to be 131N approximately

koury_with_a_k · Answer

Thank you so much for explaining @zaphodplaysitsafe!  I greatly appreciate it.  Thanks again!!

anonymous · Answer

goodluck :)

rebeccaxhawaii · Answer

$\Huge\boxed{\boxed{\boxed{\huge\mathbb{WELCOME~TO~OPENSTUDY} }}}$ Hey i have made this to hopefully answer any questions you may have. But if it doesn't feel free to pm me c: http://openstudy.com/users/rebeccaxhawaii#/updates/56f5205ce4b07a8c82287f75 Good Luck with you studies! $\Huge\heartsuit$