What is the acceleration of a car that moves in a straight line and decreases its speed from 80km/hr to 15km/hr in exactly 5.0 seconds

-3.6 m/s

Explanation:

first go from km/hr to m/s

so 80km/hr⇒ 22.2222 m/s

15km/hr ⇒4.16667 m/s

now use the equation for acceleration

(4.16667-22.2222)/5 = 18.05553/ 5 = -3.611106 m/s

with sig figs

-3.6 m/s

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

answer; equivalent to a one(1) horsepower motor;