An 88.0 kg sprinter starts a race with an acceleration of 1.60 m/s2. What is the net external force (in N) on him

The correct answer is "140.8 N".

Explanation:

Given:

Mass,

m = 88 kg

Acceleration,

a = 1.60 m/s²

Now,

The net external force for him will be:

⇒

By putting the values, we get

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