If a flea can jump straight up to a height of 21.1 cm , what is its initial speed as it leaves the ground, neglecting air resistance?

Initial speed, u = 2.03 m/s

Explanation:

Flea jumps to a height of, h = 21.1 cm = 0.211 m

As it leaves the ground, its final speed, v = 0

Acceleration, a = -g

Let u is the initial speed of the flea. It can be calculated as :

u = 2.03 m/s

So, the initial speed of the flea as it leaves the ground is 2.03 m/s. Hence, this is the required solution.

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