physics help, normal force, how much work is done,energy change?

[ethio]

A cart loaded with bricks has a total mass
of 17.7 kg and is pulled at constant speed by
a rope. The rope is inclined at 28.5 o above
the horizontal and the cart moves 21.7 m on
a horizontal floor. The coefficient of kinetic
friction between ground and cart is 0.7 .
The acceleration of gravity is 9.8 m/s2 .
What is the normal force exerted on the
cart by the floor? Answer in units of N.

How much work is done on the cart by the
rope? Answer in units of kJ.

Note: The energy change due to friction is a
loss of energy.
--What is the energy change Wf due to fric-
tion? Answer in units of kJ.