Fluid Dynamics

If wind blows at 25m/s over your house, what is the net force on the roof if its area is 240m² and is flat?

Fluid Dynamics

During each heartbeat, approximately 70cm³ is pushed from the heart at an average pressure of 105mm-Hg. Calculate the power output of the heart, in watts, assuming 70 beats per minute. *please explain this as simply as possible- thanks so much :)

Torque, center of mass

The masses of the Earth and Moon are 5.98 x 10^24kg and 7.35 x 10²²kg, respectively, and their centers are separated by 3.84 x 10^8 m. (a) where is the CM of this system located? (b) what can you say about the motion of the Earth-Moon system around the sun, and of the Earth and Moon separately around the Sun? *note- please explain this in the simplest terms possible for me- thank you so much :)

Torque, center of mass

A person exerts a force of 38N on the end of a door 96cm wide. What is the magnitude of the torque if the force is exerted (a)perpendicular to the door and (b)at a 60.0° angle to the face of the door? *note- please explain this in the simplest terms possible for me- thank you so much :)

Equilibrium

A 67.0kg adult sits at one end of a 10.0m board, on the other end of which sits his 23.0kg child. Where should the pivot be placed so the board (ignore its mass) is balanced?