Answer:
Intensity,
Explanation:
Power of the light bulb, P = 40 W
Distance from screen, r = 1.7 m
Let I is the intensity of light incident on the screen. The power acting per unit area is called the intensity of the light. Its formula is given by :
So, the intensity of light is .
Explanation:
1. study of conversion of heat to mechanics → thermodynamics
A branch of physical science which deals with heat and other forms of energy.
2. The Law of Conservation of Energy → first Law of Thermodynamics
Energy cannot be created nor be destroyed. According to first law of thermodynamics total energy of the system is always constant.
3. Result of applied energy → work
Work is the way of system to release its energy.
4. Principle that states that in any energy transformation some energy is dissipated as heat → Second Law of Thermodynamics
5. energy of motion → kinetic energy
Kinetic energy is defined as energy possessed by the body due to its motion.
6. work/displacement → force
Work is product of force and displacement.
7. power · time → energy
Power is defined energy per unit time.
8. Device that transforms heat energy into mechanical energy → heat engine
heat engine is a device which converts the heat energy which is released due to combustion of fuel into a useful work that is mechanical energy.
9 . Energy due to position → potential energy
Potential energy is defined as energy possessed by the body due to its position.
10. efficiency of a heat engine unit of heat → calorie
11. Measure of molecular motion → Temperature
Kinetic energy is directly proportional to temperature.
Greater the motion more will be the kinetic energy and with more will be the temperature.
12. Heat given off by a liquid with no change in temperature → latent heat of fusion
Latent heat of fusion is defined as heat released by 1 mole of substance when it under goes phase change that is from solid to liquid.
13. Motion within solids → vibrational motion
Vibrational motion is the motion in which particle oscillates from its mean position.
14. Phase of matter on the sun → plasma
Plasma is hot ionized gas with equal number of positive and negative ions. Due to high temperature of sun most the gas are in the plasma state.