Answer:
The size of the average force which acts on the dummy during that time=4,617 N
Explanation:
Initial Speed=u= 10.8 m/s
Final Speed=v=0 m/s
Mass=57 kg
distance=s=0.720 m
Required:
The size of the average force which acts on the dummy during that time=?
Solution:
According to 3rd equation of motion
[tex]v^2-u^2=2as[/tex]
[tex]0^2-(10.8)^2=2*a*0.720[/tex]
a=-81 m/s^2 (-ve sign for deceleration)
Note:
In calculating the force, we only use the magnitude of acceleration.
According to Newton's Second Equation:
F=ma
F=57*81
F=4,617 N
The size of the average force which acts on the dummy during that time=4,617 N
