Radio waves have the longest wavelength
Answer:
Power, P is equal to 10 watts.
Explanation:
Given the following parameters;
Voltage drop, V = 50volts.
Resistance, R = 250ohms.
Power, P =?
The power developed in an electrical circuit is given by;
......equation 1
But we also know that;
Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.
Mathematically, V = IR
Making I the subject of formula;
I = V/R
Substituting into equation 1;
P = (50²)/250
P = 2500/250
P = 10 watts.
Answer:
(d) Force of friction acts in solids, liquids and gases and opposes the motion with respect to each other.
Explanation:
The SI unit of measurement for speed is metres per second (m/s) .
Speed : The distance travelled by a body per unit time is know as speed.
Hope it will help.
Answer:
The correct answer is B
Explanation:
To calculate the acceleration we must use Newton's second law
F = m a
a = F / m
To calculate the force we use the defined pressure and the radiation pressure for an absorbent surface
P = I / c absorbent surface
P = F / A
F / A = I / c
F = I A / c
The area of area of a circle is
A = π r²
We replace
F = I π r² / c
Let's calculate
F = 8.0 10⁻³ π (1.0 10⁻⁶)²/3 10⁸
F = 8.375 10⁻²³ N
Density is
ρ = m / V
m = ρ V
m = ρ (4/3 π r³)
m = 4500 (4/3 π (1 10⁻⁶)³)
m = 1,885 10⁻¹⁴ kg
Let's calculate the acceleration
a = 8.375 10⁻²³ / 1.885 10⁻¹⁴
a = 4.44 10⁻⁹ m/s² absorbent surface
The correct answer is B
