Answer:
There are 934 excess electrons on the ball with charge -1.4944*10^(-16).
Step-by-Step Explanation:
A ball will usually be neutral and have no charge on it.
If it is negatively charged, it means there are excess electrons on it.
If we know the charge on the ball, we can count the excess no. of electrons.
We know that the charge on the ball = c = -1.4944*10^-16
Charge of one electron = e = 1.6*10^-19
Charge of n electrons on the ball = ne = c
⇒ n = c/e
n = (-1.4944*10^-16)/(1.6*10^-19)
n = 934 electrons
A) 350 J
- The initial internal energy of the cup is
- The final internal energy of the cup is
According to the first law of thermodynamics:
where
Q is the heat absorbed by the system
W is the work done on the system
The work done on the system in this case is 0, so we can rewrite the equation as
And so we find the heat transferred
B) IN the cup
Explanation:
in this situation, we see that the internal energy of the cup increases. The internal energy of an object/substance is proportional to its temperature, so it is a measure of the average kinetic energy of the molecules of the object/substance. Therefore, in this case, the temperature (and the energy of the molecules of the substance) has increased: this means that heat has been transferred INTO the system from the environment (the heat came from the sun).
Based on the information in the question, a light year is the distance traveled light in one year. Then if the light from the star Centauri takes 4.2 years to reach the earth, then its distance from earth is 4.2 light years.
Answer:
(a) 161.57 N
(b) 0.958 m/s^2
Explanation:
Force applied, F = 220 N
mass of crate, m = 61 kg
μ = 0.27
(a) The magnitude of the frictional force,
f = μ N
where, N is the normal reaction
N = m x g = 61 x 9.81 = 598.41 N
So, the frictional force, f = 0.27 x 598.41
f = 161.57 N
(b) Let a be the acceleration of the crate.
Fnet = F - f = 220 - 161.57
Fnet = 58.43 N
According to newton's second law
Fnet = mass x acceleration
58.43 = 61 x a
a = 0.958 m/s^2
Thus, the acceleration of the crate is 0.958 m/s^2.
Answer:
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