A house that is losing heat at a rate of 50,000 kJ/h when the outside temperature drops to 4 °C is to be heated by electric resistance heaters. If the house is to be maintained at 25 °C at all times, determine: a) the reversible work input for this process, and b) the irreversibility.

Mass (kg) force (n) 5 25 10 50 15 75 20 100 a student was trying to find the relationship between mass and force. he placed four different masses on a table and pulled them using a spring scale. the table shows the different masses used in the experiment and the force required to pull each mass. the student concluded that more force was required to pull heavier objects. what comment would you make regarding his conclusion? a) no clear relation can be observed between mass and force from the data. b) there is a direct proportion between the mass and force listed in the table. c) gravity should have been taken into account while performing the experiment. d) there is an inverse proportion between the mass and force listed in the table.

Erosion of the beach is normally a slow process. however, in certain situations, large chunks of shore may wash out to sea. what could cause this to happen?

What are similarities and differences of reflection, refraction, diffraction and absorption?