Answer:
T = 4.905[N]
Explanation:
In order to solve this problem we must perform a sum of forces on the vertical axis.
∑Fy = 0
We have two forces acting only, the weight of the body down and the tension force T up, as the body does not move we can say that it is system is in static equilibrium, therefore the sum of forces is equal to zero.
![T-m*g=0\\T=0.5*9.81\\T=4.905[N]](https://tex.z-dn.net/?f=T-m%2Ag%3D0%5C%5CT%3D0.5%2A9.81%5C%5CT%3D4.905%5BN%5D)
Answer : The wavelength of photon is, 
Explanation : Given,
Energy of photon = 
Formula used :

As, 
So, 
where,
= frequency of photon
h = Planck's constant = 
= wavelength of photon = ?
c = speed of light = 
Now put all the given values in the above formula, we get:


Conversion used : 
Therefore, the wavelength of photon is, 
Answer:
K = ρL²g
Explanation:
Consider L as the length of the raft inside the water when the raft is displaced through additional distance y;
Then:
F = upthrust ( restoring force) = weight of the liquid displaced.

where;
A = L²

F = ky.
Then,


Divide both sides by y
K = ρL²g
P=M(mass)G(Gravity)H(Height)
Gravity=9.8
M=1.5 G=9.8 H=35
so multiply all
=514.5 potential energy