Answer to Question #258993 in Mechanics | Relativity for fred

Question

A container ship with a displacement of 15,200 T and is sailing at 20 knots and comes to a stop after 0.75h. What is the work done on the container ship if it covers a stopping distance of 3,125 m?

Answer 1

Solution.

$m=15 200 T=15200000kg;$

$t=0.75h=2700s;$

$v_0=20knots=10.29 m/s;$

$v=0;$

$l=3125m;$

$W=Fl;$

$F=ma;$

$a=\dfrac{v-v_0}{t};$ $a=\dfrac{0-10.29}{2700}=-0.0038 m/s^2;$

$F=15200000\sdot ( -0.0038)=-57928.9N;$

$W=-57928.9\sdot 3125=-181027778J=-181MJ;$

Answer: $W=-181MJ.$