Answer:
b. 0.20 m/s.
Explanation:
Given;
initial mass, m = 0.2 kg
maximum speed, v = 0.3 m/s
The total energy of the spring at the given maximum speed is calculated as;
K.E = ¹/₂mv²
K.E = 0.5 x 0.2 x 0.3²
K.E = 0.009 J
If the mass is changed to 0.4 kg
¹/₂mv² = K.E
mv² = 2K.E
Therefore, the maximum speed is 0.20 m/s
If the comb and the paper are attracted to each other the charge on the paper, is D)must be positive
<h3>
Laws of electrical attraction</h3>
This states that
- Like charges attract
- Unlike charges repel
Now, given that a negatively charged plastic comb is brought close to, but does not touch, a small piece of paper. If the comb and the paper are attracted to each other the charge on the paper, this implies that both the negatively charged plastic comb and the paper have opposite charges.
Since the charge on the plastic comb is negative, this means that the charge on the paper must be positive
So, if the comb and the paper are attracted to each other the charge on the paper, is D)must be positive
Learn more about electric charge here:
brainly.com/question/2373424
There are two different processes here:
1) we must add heat in order to bring the temperature of the water from
to
(the temperature at which the water evaporates)
2) other heat must be added to make the water evaporates
1) The heat needed for process 1) is
where
is the water mass
is the water specific heat
is the variation of temperature of the water
If we plug the numbers into the equation, we find
2) The heat needed for process 2) is
where
is the water mass
is the latent heat of evaporation of water
If we plug the numbers into the equation, we find
So, the total heat needed for the whole process is
Air masses form because of all the moisture in the air, and they redistribute energy on the Earth's surface because of the Sun's uneven heating on the Earth allowes more energy to Earth.
Answer: 22.11 ohms
Explanation:
Potential difference(v)=420V
Current(I)=19.0 amp
Resistance(r)=?
r=v/I
r=420/19.0
r=22.11 ohms
