Thermal Energy

(a) As an egg develops into a chicken, its contents become more ordered. Does this violate the law of increasing entropy? Why? (b) In the operation of a refrigerator, does thermal energy flow from hot to cold, or is it from cold to hot? Why?

Mechanical Energy: Block Projected up the incline by spring

A block with mass m = 2.00 kg is placed against a spring on a frictionless incline with angle = 30.0° (Figure 8-43). (The block is not attached to the spring.) The spring, with spring constant k = 19.9 N/cm, is compressed 24.0 cm and then released. How Far along the incline is the highest point from the release point? I've managed to get the elastic potential energy of the spring (57.312 J) and the accompanying change in gravitational potential energy to the highest release point (also 57.312 J). Thanks!

Electric Potential Problem

An electron is projected with an initial speed of 4.8 *10^5 m/s directly toward a proton that is fixed in place. If the electron is initially a great distance from the proton, at what distance from the proton is the speed of the electron instantaneously equal to twice the initial value?

Solar Intensity on a space flight

A possible means of space flight is to place a perfectly reflecting aluminized sheet into Earth’s orbit and use the light from the Sun to push this solar sail. Suppose a sail of area 6.00 X 10^4 m^2 and mass 6000 kg is placed in orbit facing the sun. The solar intensity of 1380 W/m^2. a. What force is exerted on the sail? b. What is the sail’s acceleration? c. How long does it take the sail to reach the Moon, 3.84 X 10^8 m away? Ignore all gravitational effects and assume that the acceleration calculated in part b remains constant.

Velocity of an electron

Hello, The problem is as follows: 2 stationary point charges +3.00 nC and +2.00 nC are seperated by a distance of 50.0 cm. An electron is released from rest at a point midway between the two charges and moves along the line connecting the two charges. What is the speed of the electron when it is 10.0 cm from the +3.00 nC charge? I've tried everything, including conservation of energy. I set Potential Energy at the point x= 0.25 m equal to the sum of the Kinetic and Potential Energies at x = 0.10 m from the +3.00 charge. Then I solved for the velocity from the KE energy at x =0.10 m from the +3.00 charge as follows: v = sqrt. ((2*q*(V_a-V_b))/m) where m = mass of electron = ... click for more