1) B. Energy is the ability to do work
2) C. Energy is conserved, it just goes from one form to another.
3) Work = Force x displacement
= 300 x 100 = 30,000 Joules
4) leaning a brick because no displacement is taking place.
5) They change the amount/strength or direction of the force needed.
6) Less force is needed and applied over a longer distance.
7) Heat is the flow of thermal energy from one object to another.
Answer:
Explanation:
On both sides of the film , the mediums have lower refractive index.
for interfering pattern from above , for constructive interference of reflected wave from both sides of the film , the condition is
2μt = ( 2n +1 ) λ / 2
μ is refractive index of film ,t is thickness of film λ is wavelength of light
n is order of fringe
for minimum thickness
n = 0
2μt = λ / 2
t = λ / 4μ
= 670 / 1.75 x 4
= 95.71 nm .
As per energy conservation we know that
Energy enter into the bulb = Light energy + Thermal energy
so now we have
energy enter into the bulb = 100 J
Light energy = 5 J
now from above equation we have
The answer should be D) Cold air because even though its true sound can travel through all types of matter, air which is a gas, can travel but it travels SLOWLY while sound travels quickly in SOLIDS.
The first law of thermodynamics is expresses by
D. ΔU=Q-W
which means change in internal energy of system = Heat added to system minus work done by the system
All are expressed in Joules.
This law is based on principle of conservation of energy.
