Answer:
a) -999J
b) -793N
Explanation:
We need to apply the conversation of energy equation, we will take the potencial energy at the bottom as zero.
[tex]u1+k1+W_{friction}=u2+k2[/tex]
now rearranging the equation:
[tex]W_{friction}=u2+k2-k1\\W_{friction}=m*g*h+\frac{1}{2}*m*(v_2)^2-\frac{1}{2}*m*(v_1)^2\\W_{friction}=65.2*1.26*9.80*sin(33.3)+\frac{1}{2}*65.2*(4.54)^2-\frac{1}{2}*65.2*(8.05)^2\\W_{friction}=-999J[/tex]
we know that work is:
[tex]W=F*d\\F=\frac{W}{d}\\\\F=\frac{-635}{1.26}\\F=-793N[/tex]
