Acar traveling at 54 mph decelerates at 29 feet per second per second. how long does it take for the car to come to a complete stop

We first need to convert the 54 mph to feet per second. So converting this will give us the value of 79.2 ft per second.

Solution:

v = at 
d = 1/2 at^2 

79.2 = 29t

Dividing both sides by 29, will gives us the result of 2.73. 
meaning it takes 2.73 seconds to stop) 
d = 1/2 (29) 2.73^2 = 29.81 feet to stop.

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