Answer:
78.498N
Explanation:
The Net force provided by the spinnaker can be obtained from Newton's second law of motion as follows;
[tex]F=\frac{m(v-u)}{t}................(1)[/tex]
where m is the mass, v is the final velocity, u is the initial velocity and t is the time interval for which the force acted.
Given;
m =980lb
v = 12mi/h
u =8mi/hr
t = 10s.
It is important to convert all quantities to their SI units where necessary, so we do that as follows;
1lb = 0.45kg,
hence 980lb = 980 x 0.45kg = 441kg.
1mile = 1609.34m
1hour = 3600s,
therefore;
[tex]8mi/h=\frac{8*1609.34m}{3600s}=3.58m/s[/tex]
[tex]12mi/h=\frac{12*1609.34m}{3600s}=5.36m/s[/tex]
Substituting all values into equation (1), we obtain the following;
[tex]F=\frac{441(5.36-3.58)}{10}\\F=\frac{441*1.78}{10}\\F=\frac{784.98}{10}\\F=78.498N[/tex]
