A ball is thrown straight up with an initial speed of 30 m/s. What is its speed after 4.2 s?
2 answers:
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Answer:
They are the same
Explanation:
Electromagnetic waves consist of perpendicular oscillations of electric and magnetic field, which oscillate perpendicularly to the direction of motion of the wave (transverse wave). One property of the electromagnetic waves is that they travel in a vacuum always at the same speed, called speed of light:
Electromagnetic waves are classified into 7 different types according to their frequency; from highest to lowest frequency, we have:
Gamma rays
X-rays
Ultraviolet
Visible light
Infrared
Microwaves
Radio waves
We see that both visible light and gamma rays are electromagnetic waves, so they both travel in a vacuum at the same speed, the speed of light.
The Average velocity for the bacterium is 0.75 unit/sec.
<u>Explanation:</u>
The given values are in the vector form
Where,
dS = distance covered
dT = time interval
Now, to calculate distance covered, we have
&
d S=(4.6 i+1.9 k)-(2.2 i+3.7 j - 1.2 k)
d S=(4.6-2.2) i+(0-3.7) j+(1.9+1.2) k
d S=2.4 i-3.7 j+3.1 k
Now, putting these values in the standard formula to evaluate the average velocity, we get;
As dT=7.2 sec
Now,
Solving the equation, we get;
Hence, the average velocity for the bacterium is 0.75 unit/sec.