As a substance is changing from a liquid to a gas, the distance between its molecules increases, and the temperature of the system remains the same.
Option A
<u>Explanation:</u>
The external energy required to change from one state to another is mostly considered as temperature. So on increase in temperature, the solid changes to liquid and the liquid changes to gases. But the temperature remains constant in the system after changing the phase.
This is because when the temperature is increased on a liquid system, the rise in temperature is utilized for breaking the bonds and thus the molecules will be distanced from each other. If we consider liquid - gas phase transition, the gas molecules are farther distanced compared to liquid molecules.
So the rise in temperature is utilized for breaking the bonds and also to provide the kinetic energy to the gas molecules as they are tend to move more freely compared to liquid. Thus, the distance between the molecules increases, and the temperature of the system remains the same on changing from liquid to gas.
If you don't have the coefficient of absorption, I would say Heavy curtains.
Hope this helps :)
Answer:
Explanation:
Range of projectile R = 20 m
formula of range
R = u² sin2θ / g
u is initial velocity , θ is angle of projectile
putting the values
20 = u² sin2x 40 / 9.8
u² = 199
u = 14.10 m /s
At the initial point
vertical component of u
= u sin40 = 14.1 x sin 40
= 9.06 m/s
Horizontal component
= u cos 30
At the final point where the ball strikes the ground after falling , its speed remains the same as that in the beginning .
Horizontal component of velocity
u cos 30
Vertical component
= - u sin 30
= - 9.06 m /s
So its horizontal component remains unchanged .
change in vertical component = 9.06 - ( - 9.06 )
= 18.12 m /s
change in momentum
mass x change in velocity
= .050 x 18.12
= .906 N.s
Impulse = change in momentum
= .906 N.s .
Since the bulb consumes 100 watts of power and its efficiency is 95%,
it generates 95 watts of light energy and 5 watts of heat energy whenever
it's turned on.
5 watts means 5 joules of energy per second.
(2.5 hours) x (3,600 seconds/hour) = 9,000 seconds
(9,000 seconds) x (5 joules/second) = 45,000 joules of heat in 2.5 hours
The buoyant force must be greater than water.
