You pull on a shopping cart with a net force of 25 n to the left. your friend pulls on the same shopping cart with a net force of 25 n to the right. describe the motion of the shopping cart.

The shopping cart is in equilibrium since the net force acting on it is zero
net force = 25 N - 25 N
net force = 0 N
meaning the shopping cart is not moving because the force exerted by me is counter acted by force acted by my friend. meaning the forces just cancels out and leads to zero net force and no motion 

the energy generated by an individual's metabolism is calculated in met (metabolic equivalent of task). the met is the ratio of the work metabolic rate to the resting metabolic rate. one met is illustrated as 1 kcal per kilogram per hour, and is probably equal to the energy cost of sitting quietly.

1 met is equal to 1.162 watt per kg

1 kg is equal to 1000 grams

as the person weighs 80000 gm, that is, 80 kg.

therefore, 80*1.162 = 92.96

thus, the person expends 92.96 watts of power while at rest.