Answer:
The correct option is (b).
Explanation:
Given that,
At the top of the hill, the kinetic energy is E and the gravitational potential energy is 3E.
We need to find the kinetic energy of the car on the ground.
We know that,
Mechanical energy = kinetic energy + potential energy
According to the law of conservation of energy, the total mechanical energy is conserved.
It means, when it coasts down to ground level, the kinetic energy is same as that on the top of the hill. Hence, the required kinetic energy on the ground is equal to 3E.
It would be not be able to move yet it would be in the air
In order to calculate the temperature, we need to know that temperature and pressure are directly proportional, that is, if the pressure increases, the temperature (in Kelvin) also increases in the same proportion.
So, first let's convert the temperature from Celsius to Kelvin, by adding 273 units:
Then, let's calculate the proportion:
Now, converting back to Celsius, we have:
So the temperature would be 166.5 °C.
Answer:
8 KJ/ s
Explanation:
Heat pumps Transfer thermal energy through absorbing of heat that comes from cold region and then release to warmer area by utilizing external power.
The coefficient of performance known as COP provide the ratio of both heating and cooling that are supplied to required work.
✓QH=The rate at which heat is produced = ?
✓COP= Coefficient of performance of a residential heat pump = 1.6
✓ W(in)= power consumption= 5KW
QH=The rate at which heat is produced=[Coefficient of performance of a residential heat pump] × [power consumption]
= 1.6 × 5KW
=8 KJ/ s
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