Dr. john paul stapp was u. s. air force officer who studied the effects of extreme deceleration on the human body. on december 10, 1954, stapp rode a rocket sled, accelerating from rest to a top speed of 282m/s (1015km/h) in 5.00s, and was brought jarringly back to rest in only 1.40s! calculate the magnitude of his (a) acceleration as he sped up and (b) acceleration as he slowed down. express each in multiples of g (9.80 m/s2) by taking its ratio to the acceleration of gravity.

acceleraions 5.76g and 20.55g

Explanation:

This constant acceleration exercise can be solved using the kinematic equations in one dimension

    Vf = Vo + a t

As part of the rest Vo = 0

    a = Vf / t

    a = 282/5

    a = 56.4 m / s2

In relation to the acceleration of gravity

    a ’= a / g = 56.4 / 9.8

    a ’= 5.76g

To calculate the acceleration to stop we use the same formula

     a2 = 282 / 1.40

     a2 = 201.4 m / s2

 This acceleration of gravity acceleration function is

     a2 ’= 201.4 / 9.8

     a2 ’= 20.55g

power out to power in less than 100%

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west