Answer:
40J
Explanation:
Kinetic energy = 1/2 mv^2
Where m = mass and
v = velocity
Given mass = 20kg
v = 2m/s
K.E = 1/2 x 20 x2^2
= 1/2 x 20 x 2 x 2
= 80/2
= 40J
As per the question the wavelength of the microwave is given as 3.52 mm.
we are asked to calculate the frequency of the wave.
we know that microwave is a electromagnetic wave.
As per Clark Maxwell's electromagnetic theory ,every electromagnetic wave moves with a velocity equal to the velocity of light in vacuum and that is equal to 3×10^8 m/s.
From the equation of the wave,we know that velocity of wave is the product of frequency and wavelength.
Mathematically wave velocity 
where f is the frequency of the wave and 
is the wavelength.
As per the question 
Here 
Hence frequency of the wave 
Here Hertz [Hz] is the unit of frequency.
Answer:
You can describe the<u> motion </u>of an object by saying it is moving in a straight line or is curved around another object. You can also describe where an object is by its <u> position </u> in relation to another object. The second object acts as a<u> reference</u> point. When an object changes position, you know it has motion. Motion can also be described by finding an object's <u>speed </u>or how fast or slow it moves in a certain amount of time. In addition, you can describe the object's speed AND direction together. This is called <u>velocity</u>
Explanation:
In the given answer-
<u>Motion</u> is defined as - the change in the movement or position of any object or body.
<u>Position</u> is said to be a place or somewhere or a location where any object or body is particularly placed/located or put on.
<u>Reference poin</u>t is a fixed point with regards to which any object or body changes its position. It is also called reference origin.
<u>Speed</u> is defined as the rate of any object covering certain distances. It is a scaler quantity (quantity which depends upon only magnitude).
<u>Velocity</u> is defined as the rate of speed per unit time. It is a vector quantity (quantity depending upon both magnitude and direction ).
Answer:
10s
Explanation:
If it took Beatrice 25 seconds to complete the race
Distance = 100 meter
Beatrice speed = 100/25
= 4m/s
If Alice runs at a constant speed and crosses the finish line $5$ seconds, she must have completed the race in 20s (25 -5).
Her speed where constant
= 100/20
= 5 m/s
It would take Alice
= 50/5
= 10s
It would take Alice 10s to run $50$ meters.
Answer:
the branch of mechanics concerned with the interaction of electric currents with magnetic fields or with other electric currents.
Explanation:
