Answer to Question #166717 in Classical Mechanics for Rica

Question

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 282 m/s (1015 km/h) in 5.00 s, and was brought jarringly back to rest in only 1.40 s!

Answer 1

Given,

Initial velocity $(v_i)=0$

Final velocity $(v_f)=282 m/s$

Time taken $(t)=5.0 sec$

Acceleration of the particle $(a) = \frac{v_f-v_i}{t}$

Now, substituting the values,

$a=\frac{282}{5} m/s^2$

$\Rightarrow a = 56.4 m/s^2$

Acceleration in terms of g ,

$a_g= \frac{56.4g}{9.8}=5g m/s^2$

It comes in rest in 1.4s so retardation $a_r= \frac{-282}{1.4} m/s^2$

$=201.43 m/s^2$

Retardation in terms of g,

$a_{rg}=\frac{201.43g}{9.8} m/s^2$

$=-20.5g m/s^2$