Answer:
Mass, m = 4 kg
Explanation:
<u>Given the following data;</u>
Energy = 3.6 * 10^17 Joules
We know that the speed of light is equal to 3 * 10⁸ m/s.
To find the mass of the substance;
The theory of special relativity by Albert Einstein gave birth to one of the most famous equation in science.
The equation illustrates, energy equals mass multiplied by the square of the speed of light.
Mathematically, the theory of special relativity is given by the formula;

Where;
- E is the energy possessed by a substance.
- m is the mass.
- c is the speed of light.
Substituting into the formula, we have;



Mass, m = 4 kg
Answer:
b) 0.5 m/s
Explanation:
let V be the averare speed of the object.
the average speed is given by:
V = total distance / total time
= (20+20)/(30+50)
= 0.5 m/s
Therefore, the average speed of the object is 0.5 m/s.
Answer:
The path difference between the two waves should be one-half of a wavelength
Explanation:
When two beams of coherent light travel different paths, arriving at point P. If the maximum destructive interference is to occur at point P , then the condition for it is that the path difference of two beams must be odd multiple of half wavelength. Symbolically
path difference = ( 2n+1 ) λ / 2
So path difference may be λ/2 , 3λ/ 2, 5λ/ 2 etc .
Hence right option is
The path difference between the two waves should be one-half of a wavelength.
<h2>Answer:</h2>
The part of the electromagnetic spectrum usually used for communication is of radio waves, infrared waves and microwaves.
But most common waves used in communication are radio waves.
<h3>Explanation:</h3>
- Radio waves are used to transmit television and radio programmes.
- While microwaves are used for mobile phones and Wi-Fi.
- Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.
- Radio waves have frequencies as high as 300 gigahertz (GHz) to as low as 30 hertz (Hz).
Both vehicles experience the same change in momentum.
When the compact car rear ends a truck, they exert equal forces on each other, in accordance with Newton's third law. The force exerted by the car on the truck is equal to the force exerted by the truck on the car.The force acting on the two bodies act for the same interval of time.
According to Newton's second law, the force acting on a body is equal to the rate of change of momentum.
Since the forces are equal,

therefore, the change in momentum of the car
is equal to the change in the momentum of the truck
.
Thus, both the car and the truck experience the same change in their momentum. However due to the smaller mass of the car, the change in its velocity is greater than the change in the truck's velocity, which has a larger mass.