A sphere of density = 500 kg/m^3 floats on water (density of water = 1000 kg/m^3).
1. What fraction of the volume of the sphere is below the waterline?
---I understand this problem and I got the correct answer of 0.5
2. Another liquid of density 200 kg/m^3 is now added on top of the water. The...
A lawnmower engine with an efficiency of 0.22 rejects 9900 J of heat every second. What is the magnitude of the work that the engine does in one second?
e = 0.22
Qc = 9900 J/s
e = W/Qh
Qh = Qc + W
e = W / Qc + W
0.22 = W / 9900 + W
0.22(9900 + W) = W
2178 + 0.22W = W
W = 2792.31...
If an area of 1 m2 at the Earth surface emits Q/t = 54E-3 J/s in radiation, what would the temperature at the Earth surface be, if there would be no other energy sources? Assume that the Earth is a perfect black body emitter (e = 1).
Q/t = e(5.67E-8)(A)T4
54E-3 = 1(5.67E-8)T4
T = 31.2 K?
The...
Imagine a diamond sphere radius of 1 cm traveling in space far from any heat sources. Embedded in the center of the sphere is a magic heater that can produce 0.3 W for an indefinite amount of time.
If the emissivity of the surface is zero, what temperature does the sphere reach? Why?
The...
A meat baster consists of a squeeze bulb attached to a plastic tube. When the bulb is squeezed and released, with the open end of the tube under the surface of the basting sauce, the sauce rises in the tube to a distance h, as the drawing shows. Using 1.013 × 1055Pa for the atmospheric pressure...
----Unsolved----Work, Energy problem and friction
EEEK I already posted this problem, but I cannot find it anymore! SO here it is again!
A student, starting from rest, slides down a water slide. On the way down, a kinetic frictional force (a nonconservative force) acts on her. The student has...
A student, starting from rest, slides down a water slide. On the way down, a kinetic frictional force (a nonconservative force) acts on her. The student has a mass of 70 kg, and the height of the water slide is 11.3 m. If the kinetic frictional force does -7.6 × 103 J of work, how fast is the...
The moon has a diameter of 3.48 x 10^6 m and is a distance of 3.85 x 10^8m from the earth. The sun has a diameter of 1.39 x 10^9 m and is 1.50 x 10^11 m from the earth.
(a.) What are the angles (in radians) subtended by the moon and the sun, as measured by a person standing on the earth...
A jet is circling an airport control tower at a distance of 18.0 km. An observer in the tower watches the jet cross in front of the moon. As seen from the tower, the moon substends an angle of 9.04 x 10-3 radians. Find the distance traveled (IN METERS) by the jet as the observer watches the nose...