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A friend claims that as long as he has his seat belt on, he can hold on to a 14 kg child in a 64 mi/h head-on collision with a brick wall in which the car passenger compartment comes to a stop in 0.05 s. Show that the violent force during the collision will tear the child from his arms. A child should always be in a toddler seat secured with a seat belt in the back seat of a car.

Answer :

Boffeemadridgo

Answer:

Force is too large for a person to exert.

Explanation:

m = Mass of child = 14 kg

u = Initial velocity of compartment = 64 mi/h = [tex]\dfrac{64\times 1609.34}{3600}=28.61\ \text{m/s}[/tex]

v = Final velocity of compartment = 0

t = Time taken by the compartment to stop = 0.05 s

Force is given by

[tex]F=ma\\\Rightarrow F=m\dfrac{v-u}{t}\\\Rightarrow F=14\times \dfrac{0-28.61}{0.05}\\\Rightarrow F=-8010.8\ \text{N}[/tex]

The person has to exert a force of [tex]-8010.8\ \text{N}[/tex] in the opposite direction to keep holding the child. This is a huge amount of force and cannot be done by a person's physical strength alone.

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