The container is filled with equal masses of water and oil. The oil floats on top of water (density 1000 kg/m3), and the open surface of the oil is at a height h above the bottom of the container. What is the height h if the pressure at the bottom of the water is 400 kPa greater than the pressure at the top of the oil? Assume the oil density is 600 kg/m3. The height = hoil + hwater.
Hint: Express the volumes of oil and water in cylinder in order to get the relationship between the height of the fluid and its density. Note that density = mass / Volume. Remember m of oil = m of water.
The longer a straw, the harder it is to drink from. If the air pressure is 91200 Pa, and if you could create a perfect vacuum in your mouth, what is the maximum length of a straw that you could still drink from? Density of water: 1000kg/m^3. Ignore capillary effects.
A uniform strut (i.e. a beam! I like to use fancy words!) of 130 kg is fixed on the ground by a hinge. The cable is attached at the other end and a 225 kg mass is also attached at the end.
I found the tension at 7772.4N and the horizontal component of the force exerted by the hinge on the strut at
6731.1 N. I can't find the vertical component of the force exerted by the hinge on the strut. I thought that because the angle is at 45deg, it would be the same as the x-component, but I got the answer wrong.
What am I doing wrong?Physics2 years ago
The six particles (of negligible size) in the figure opposite are connected together by rigid rods of negligible mass. The system forms a perfect hexagon of side 2 m, and the particles have a mass of 1 kg each.
a) Calculate the moment of inertia (no unit needed) of the system about an axis perpendicular to the plane and passing through the centre of mass of the system.
b) Calculate the moment of inertia (no unit needed) of the system about an axis parallel to the one in (a), but passing through one of the masses.5 AnswersPhysics2 years ago