Answer:
4 A
Explanation:
The relationship between current, voltage and resistance in a circuit is given by Ohm's law:
where
V is the voltage
R is the resistance
I is the current
The equation can also be rewritten as
from which we see that the current is inversely proportional to the resistance, R.
In this problem, the initial current is I = 8 A. Then the resistance is doubled:
R ' = 2R
So the new current is
so the current is halved.
Twenty is the atomic number of potassium.
Answer:
–735.17 N
The negative sign indicate that the force is acting in opposition direction to the car.
Explanation:
The following data were obtained from the question:
Mass (m) of car = 782.10 kg
Initial velocity (u) = 7.60 m/s
Final velocity (v) = 3.61 m/s
Time (t) = 4.23 s
Force (F) =?
Next, we shall determine the acceleration of the car. This can be obtained as follow:
Initial velocity (u) = 7.60 m/s
Final velocity (v) = 3.61 m/s
Time (t) = 4.23 s
Acceleration (a) =?
a = (v – u) / t
a = (3.61 – 7.60) / 4.23
a = –3.99 / 4.23
a = –0.94 m/s²
Finally, we shall determine the force experienced by the car as shown below:
Mass (m) of car = 782.10 kg
Acceleration (a) = –0.94 m/s²
Force (F) =?
F = ma
F = 782.10 × –0.94
F = –735.17 N
The negative sign indicate that the force is acting in opposition direction to the car.
Answer:
Two of Einstein’s influential ideas introduced in 1905 were the theory of special relativity and the concept of a light quantum, which we now call a photon. Beyond 1905, Einstein went further to suggest that freely propagating electromagnetic waves consisted of photons that are particles of light in the same sense that electrons or other massive particles are particles of matter. A beam of monochromatic light of wavelength \lambda (or equivalently, of frequency f) can be seen either as a classical wave or as a collection of photons that travel in a vacuum with one speed, c (the speed of light), and all carrying the same energy, {E}_{f}=hf. This idea proved useful for explaining the interactions of light with particles of matter.
