Answer
a) $J=38,427\ Ns$
b) $192,133 \ N$
c) $2767\ kg$
Work Step by Step
a) We know that the impulse equals the integral of the F(t) function:
$J = \int_0^.2(at^4+bt^3+ct^2+d)dt$
Plugging in the given constants and taking the integral, we find:
$J=38,427\ Ns$
b) The average force equals the impulse divided by the change in time:
$F_{avg}=\frac{38,427}{.2}=192,133 \ N$
c) We use Newton's second law:
$m=\frac{F}{a} = \frac{192,133}{69.44}=2767\ kg$
