a.
•$W_{A}$ = $\dfrac{1}{2}$m$v_{A}^2$ + mg$z_{A}$
<=>$W_{A}$ = ($\dfrac{1}{2}$.$5^2$ + 10.10)m
=> $W_{A}$ = 112,5m (J)
• $W_{A}$ = mg$h_{max}$
<=> 112,5 = 10.$h_{max}$
=> $h_{max}$ = 11,25 (m)
b.
$W_{A}$ = $Wđ_{B}$ + $Wđ_{B}$
<=> 112,5m = 2.$\dfrac{1}{2}$m$v_{B}^2$
<=> 112,5 = $v_{B}^2$
=> $v_{B}$ = $\dfrac{15\sqrt{2}}{2}$ (m/s)
c.
W = 112,5m = 112,5.0,2 = 22,5 (J)