Answer:
0.5kg
Explanation:
Given parameters:
Potential energy = 147J
Height = 30m
Unknown:
Mass of the bird = ?
Solution:
Potential energy is the energy due to the position of a body. Now, the expression for finding the potential energy is given as;
P.E = mgH
m is the mass
g is the acceleration due to gravity = 9.8m/s²
H is the height
147 = m x 9.8 x 30
m = 0.5kg
Answer : The temperature when the water and pan reach thermal equilibrium short time later is,
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.
where,
= specific heat of aluminium =
= specific heat of water =
= mass of aluminum = 0.500 kg = 500 g
= mass of water = 0.250 kg = 250 g
= final temperature of mixture = ?
= initial temperature of aluminum =
= initial temperature of water =
Now put all the given values in the above formula, we get:
Therefore, the temperature when the water and pan reach thermal equilibrium short time later is,
Answer: The wave can flip upside down.
Reflection is the bending of a wave when it cannot pass through. For example, plain mirrors which are flat, a ray of light hits the mirror and is reflected from the mirror since it cannot pass through
When reflection occurs the speed and frequency of the wave does not change but the wave is flipped upside down.
The speed does not change because speed is affected by the change in medium the frequency also remains the same since the energy of the wave does not change.