Answer:
The time taken by the brick to hit the ground, t = 0.84 s
Explanation:
Given that,
A brick falls from a height, h = 3.42 m
The initial velocity of the brick is zero.
Since the brick is under free-falling. The time equation of a free-falling body when the displacement is given is
t =
where,
h - height from surface in meters
g - acceleration due to gravity
on substituting the values in the above equation,
t =
= 0.84 s
Hence, time taken by the brick to hit the ground is t = 0.84 s
Answer:
Explanation:
The energy of a photon is given by:
(1)
Where:
is the Planck constant
is the frequency light
On the other hand, there is an inverse relationship between and the wavelength
:
(2)
Where:
is the speed of light
is the wavelength
Substituting (2) in (1):
(3)
Finally:
This is the energy of a photon of blue light, in Joules.
Answer:
B, C and E
Explanation:
The unit of resistance in the international system is the Ohm, the equation that describes the resistance is:
Where (l) is for lenght of the wire, (S) is the area and (p) its the constant associated to the conductor.
It's related by the Ohm's Law: