Answer:
External force on him will be 112 N
Explanation:
We have given the mass of the sprinter m =70 kg
Acceleration of the sprinter 
We have to find the net external force
According to second law of motion force = mass ×acceleration
Force is dependent on the mass and acceleration
So 
So external force will be 112 N
Answer:
Energy output from Solar panel is Electric Energy so any object which require electric energy an input will run by turbine. for example Electric Bulb,Electric Water Heaters.
hope it helps you!!
I believe there are two correct answers, and those answers are A and D