Answer:
a. ΔP/Δt = 42.6 N
b. F = 42.6 N
c. P = 142042.4 Pa = 1.42 KPa
Explanation:
a.
First, we find the change in momentum of the bullets. For one bullet:
ΔP = m(Vf - Vi)
where,
ΔP = Change in Momentum = ?
m = mass of bullet = 5 x 10⁻³ kg
Vf = Final Speed = 1110 m/s
Vi = Initial Speed = 0 m/s (Since bullets are initially at rest)
Therefore,
ΔP = (3 x 10⁻³ kg)(1110 m/s - 0 m/s)
ΔP = 3.33 N.s
For 151 bullets:
ΔP = (151)(3.33 N.s)
ΔP = 502.83 N.s
Now, dividing this by time interval, Δt = 11.8 s
ΔP/Δt = 502.83 N.s/ 11.8 s
<u>ΔP/Δt = 42.6 N</u>
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b.
According to Newton's Second Law, the force is equal to rate of change of linear momentum:
Average Force = F = ΔP/Δt
<u>F = 42.6 N</u>
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c.
The pressure is given by:
Average Pressure = P = Average Force/Area
P = 42.6 N/ 3 x 10⁻⁴ m²
<u>P = 142042.4 Pa = 1.42 KPa</u>