Energy in Thermal Processes

A 60kg runner expends 300W of power while running a marathon. Assuming that 10% of the energy is delivered to the muscle tissue and that the excess energy is primarily removed from the body by sweating, determine the volume of bodily fluid (assume it is water) lost per hour. (At 37degree C the latent heat of vaporization of water is 2.41*10^6J/kg) Thermal Conductivities for water = 0.6J/s*m*C Latent Heats of Fusion and Vaporization: Melting point-0.00 Latent Heat of Fusion-3.33*10^5J/kg Boiling point-100C Latent Heat of Vaporization-2.26*10^6J/kg Specific Heat at Atmospheric Pressure-4186J/kg*C The other problem I have, I got the answer but Not sure of the steps to get the a... click for more

What is the weight of a 66-kg astronaut (a) on Earth (b) on the moon (g=1.7m/s2, (c) on Mars(g=3.7m/s(square) , (d) in outer space traveling with constant velocity?

1. A 0.140-KG BASEBALL TRAVELING 45.0m/s strikes the catcher's mitt,which in bringing the ball to rest, recoils backward 11.0 cm. What was the average force applied by the ball on the glove. 2.A box weighing 70(newtons) rests on a table.A ROPE TIED TO THE BOX RUNS VERTICALLY UPWARD OVER A PULLEY AND A WEIGHT IS HUNG FROM THE OTHER END. Determine the force that the table exerts on the box if the weight hanging on the other side of the pulley weighs (a)30N (b)60N (c)90N

Basic Thermal....Other Problems that are basic.

1.A space vehicle returning to Earth is fist slowed by its motors to a speed of 450m/s and then is slowed further to 100m/s by air resistance in the atmosphere. Its average heat capacity is 0.60kJ/kg-Cdegrees. Find the increase in its temperature on the assumption that 70% of the heat produced is absorbed by the vehicle and that it is distributed uniformly through vehicle. 2.A downhill skier of mass 80kg arrives at the last 500m stretch of his run after a big turn which slows him to 22m/s. The remaining slope is at 25 deg. Given that the friction coefficient between his skis and the snow is 0.14, and assuming that all the energy lost due to friction is used to melt the snow sticking ... click for more

The Gravitational Force

Three uniform spheres are located at the corners of an equilateral triangle. Each side of the triangle has a length of 1.20 meters. Two of the spheres have a mass of 2.80 kg each. The third sphere (mass unknown) is released from rest. Considering only the gravitational forces that the spheres exert on each other, what is the magnitude of the initial acceleration of the third sphere?

Working with centripetal acceleration and force.

A child is twirling a 0.0120 kg ball on a string in a horizontal circle whose radius is 0.100 m. The ball travels once around the circle in 0.500 s. (a) Determine the centripetal force acting on the ball. (b) If the speed is doubled, does the centripetal force double? If not, by what factor does the centripetal force increase?