An 800 N man climbs 5 m up a ladder. How much gravitational potential energy does he gain?

4000J

Explanation:

Given parameters:

Weight of the man  = 800N

Height of ladder  = 5m

Unknown:

Gravitational potential energy gained  = ?

Solution:

The gravitational potential energy is due to the position of a body.

 Gravitational potential energy = weight x height

Now insert the parameters;

 Gravitational potential energy  = 800 x 5  = 4000J

given data:

determine the horse power (h.p) = ?

force applied to move the box(f) = 10 pounds,

box lifted from a distance         (d) = 3 feet

time taken to lift                         (t) = 10 sec,

the horse power is defined as amount of work required to move a load. the horse power is equal to 550 foot-pound per second

                  1 h.p   = 550 foot-pound/second

it can also be defined as the the load that need to be move a body for certain distance in a certain amount of time.

mathematically,

                      h.p = (force × distance)/ time

                            = (10 × 3)/ 10

                            = 30/10

                            = 3 foot -pound/sec

hence, the horse power is needed to move the box is 3 foot-pound/second

important note: 1 h.p = 550 foot-pound/second = 746 watts