The heat (energy) needed to raise the temperature of the water is given by

The wavelength of the radiation of the oven is

, so the energy of a single photon of this radiation is

So, the number of photons required to heat the water is the total energy absorbed by the water divided by the energy of a single photon:

photons
Answer:
(a) T = 2987.6 k
(b) T = 19986.2 k
Explanation:
The temperature of a star in terms of peak wavelength can be given by Wein's Displacement Law, which is as follows:

where,
T = Radiated surface temperature
= peak wavelength
(a)
here,
= 970 nm = 9.7 x 10⁻⁷ m
Therefore,

<u>T = 2987.6 k</u>
(b)
here,
= 145 nm = 1.45 x 10⁻⁷ m
Therefore,

<u>T = 19986.2 k</u>
Answer:
4 m/
Explanation:
From Equilibrium of forces, The Tension in string is cancelled by the Weight (product of mass and acceleration due to gravity) of the body acting downwards.
The Net force = Mass * Acceleration.
Since Net Force = 20 Newton, Mass = 5kg, therefore;
20 = 5kg * acceleration. Dividing the RHS and LHS of the equation by 5, we have;
Acceleration =
which gives 4.
Note: RHS means Right Hand Side.
LHS means Left Hand Side.
25/1500 is equal to 0.8/x
0.8*1500 is equal to 1200
1200/25 is equal to 48 N
Answer:
, where the minus indicates the direction is opposite to that of the throw.
Explanation:
a)
Since MKS stands for meter-kilogram-second and we know that:



We can write that:



These are conversion factors, equal to 1, so multiplying our results by them won't change their value, only their units.
So we have that:



b)
Newton's 2nd Law tells us that F=ma, and the definition of acceleration is
, so we have:

Taking the throw direction as the positive one, for our values we have:
