Sarah, who has a mass of 55 kg, is riding in a car at 20 m/s. She sees a cat crossing the street and slams on the brakes! Her seatbelt stops her from flying forward, bringing her to rest in 0.5 seconds
F = (mass)(acceleration) = ma
m = 55 kg
Vi = 20 m/s
t = 0.5 s
Vf = 0 m/s (since she was put to rest)
a=(Vf-Vi)/t
a=(0-20)/5
a = 40 m/s^2 (decelerating)
F = ma = (55 kg)(40 m/s^2)
F = 2200 N
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this answer will be a good help for you.
Answer:
Force = 2200 N
Step-by-step explanation:
Given : Mass = 55 kg , Velocity of car = 20 m/s , time=0.5 s
To find : Force did the seat belt put on Sarah.
Force = (mass)(acceleration) = ma
Acceleration= (Final velocity - initial velocity) / time
Final velocity \(V_f = 20 m/s\) , Initial velocity \(V_i= 0\) (after break car is at rest), time(t) =0.5 seconds
\(a=\frac{V_f-V_i}{t}\)
\(a=\frac{20-0}{0.5}\)
\(a=40 m/s^2\)
Force = mass × acceleration
\(F=m\times a = (55 kg)(40 m/s^2)=2200 N\)
Therefore, F = 2200 N