A, Lenz' Law. There need to be a difference of flux, so if you use AC you will get a current too.
(a) The kinetic energy of the projectile when it reaches the highest point in its trajectory is 900 J.
(b) The work done in firing the projectile is 2,500 J.
<h3>
Kinetic energy of the projectile at maximum height</h3>
The kinetic energy of the projectile when it reaches the highest point in its trajectory is calculated as follows;
K.E = ¹/₂mv₀ₓ²
where;
- m is mass of the projectile
- v₀ₓ is the initial horizontal component of the velocity at maximum height
<u>Note:</u> At maximum height the final vertical velocity is zero and the final horizontal velocity is equal to the initial horizontal velocity.
K.E = (0.5)(2)(30²)
K.E = 900 J
<h3>Work done in firing the projectile</h3>
Based on the principle of conservation of energy, the work done in firing the projectile is equal to the initial kinetic energy of the projectile.
W = K.E(i) = ¹/₂mv²
where;
- v is the resultant velocity
v = √(30² + 40²)
v = 50 m/s
W = (0.5)(2)(50²)
W = 2,500 J
Thus, the kinetic energy of the projectile when it reaches the highest point in its trajectory is 900 J.
The work done in firing the projectile is 2,500 J.
Learn more about kinetic energy here: brainly.com/question/25959744
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Answer:
B
Explanation:
this is because the neutrons do not have a charge, the things that have charge in an atom are electrons and protons.
and in the nucleus of an atom, there are protons and neutrons so you can see that A is not the answer
if you see the periodic table, you will know that the number of electrons and protons are equal, so the charges cancel each other out, hence the charge of an atom will be neutral
let me give you a tip which I got from my teacher, never write there is no charge in the atom, this suggests that there is no protons or electrons.
instead, write, the it is neutral
hope it helps if not please report it so that someone else gets to try it out
The quantity of heat must be removed is 1600 cal or 1,6 kcal.
<h3>Explanation : </h3>
From the question we will know if the condition of ice is at the latent point. So, the heat level not affect the temperature, but it can change the object existence. So, for the formula we can use.

If :
- Q = heat of latent (cal or J )
- m = mass of the thing (g or kg)
- L = latent coefficient (cal/g or J/kg)
<h3>Steps : </h3>
If :
- m = mass of water = 20 g => its easier if we use kal/g°C
- L = latent coefficient = 80 cal/g
Q = ... ?
Answer :

So, the quantity of heat must be removed is 1600 cal or 1,6 kcal.
<u>Subject : Physics </u>
<u>Subject : Physics Keyword : Heat of latent</u>