Question

After World War II the U.S. Air Force carried out experiments on the amount of acceleration a human can survive. These experiments, led by John Stapp, were the first to use crash dummies as well as human subjects, especially Stapp himself, who became an effective advocate for automobile safety belts. In one of the experiments, Stapp rode a rocket sled that decelerated from 140 m/s (about 310 mi/h) to 70 m/s in just 0.6 s.
(a) What was the absolute value of the (negative) average acceleration?
m/s2

(b) The acceleration of a falling object if air resistance is negligible is 9.8 m/s/s, called "one g." What was the absolute value of the average acceleration in g's? (Stapp eventually survived a test at 46 g's!)
g

Answer 1

Answer:

11.9051g

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

g = Acceleration due to gravity = 9.8 m/s²

$v=u+at\\\Rightarrow a=\dfrac{v-u}{t}\\\Rightarrow a=\frac{70-140}{0.6}\\\Rightarrow a=-116.67\ m/s^2$

Absolute value of the (negative) average acceleration is 116.67 m/s²

$\dfrac{a}{g}=\dfrac{116.67}{9.8}\\\Rightarrow a=11.9051g$

The deceleration was 11.9051g