During each heartbeat, about 80 g of blood is pumped into the aorta in approximately 0.2 s. during this time, the blood is accelerated from rest to about 1 m/s.

I assume that in this item, we are asked to solve for the force exerted during the heartbeat. Force is the product of the mass and acceleration. To solve for the acceleration in this item, we divide the velocity by time.
                                   a = 1 m/s /  0.2 s = 5 m/s²
Then, we multiply this by the mass (in kg)
                                  F = (80 g / 1000 g/kg) x (5 m/s²)
                                      = 0.4 kg m/s² = 0.4 J
Therefore, every hearbeat will take 0.4 J of force. 

Ithink your answer will be c hope that’s you