The heat required to change 1.25 kg of steak is 2825 kJ /kg.
<u>Explanation</u>:
Given, mass m = 1.25 kg, Temperature t = 100 degree celsius
To calculate the heat required,
Q = m
L
where m represents the mass in kg,
L represents the heat of vaporization.
When a material in the liquid state is given energy, it changes its phase from liquid to vapor and the energy absorbed in this process is called heat of the vaporization. The heat of vaporization of the water is about 2260 kJ/kg.
Q = 1.25
2260
Q = 2825 kJ /kg.
Answer:
U² = 142.86 N
U¹ = 357.14 N
Explanation:
Taking summation of the moment about point A, we get the following equilibrium equation: (taking clockwise direction as positive)

where,
W = weight of boy = 500 N
U² = reaction ay B = ?
Therefore,

<u>U² = 142.86 N</u>
Now, taking summation of forces on the plank. Taking upward direction as positive, for equilibrium position:

<u>U¹ = 357.14 N</u>
Explanation:
As we know that relation between energy and wavelength is as follows.
E = 
This means that energy is inversely proportional to wavelength. So, more is the energy of an electromagnetic radiation less will be its wavelength.
Also, f = 
Hence, less will be the wavelength more will frequency of a radiation.
Gamma rays are the rays that have highest energy, small wavelength and highest frequency.
Thus, we can conclude that gamma rays are the electromagnetic radiation which has the highest frequency.