They are called mechanical waves
<span>When temperature is increased,
the rate of dissolving increases. The kinetic energy of the molecules of the
solute and solvent molecules is high thereby increasing their contact. An example
is mixing powdered sugar to the water. When you add water to the sugar, the
dissolving process is slow. However, when you increase the temperature of the
water by boiling it, the sugar dissolves immediately. </span>
1) The average velocity is 
2) The instantaneous velocity is 
Explanation:
1)
The average velocity of an object is given by

where
d is the displacement
t is the time elapsed
In this problem, the position of the particle is given by the function

where t is the time.
The position of the particle at time t = 6 sec is

While the position at time t = 12 sec is

So, the displacement is

And therefore the average velocity is

2)
The instantaneous velocity of a particle is given by the derivative of the position vector.
The position vector is

By differentiating with respect to t, we find the velocity vector:

Therefore, the instantaaneous velocity at any time t can be found by substituting the value of t in this expression.
Learn more about velocity:
brainly.com/question/5248528
#LearnwithBrainly
Answer:
²₁H + ³₂He —> ⁴₂He + ¹₁H
Explanation:
From the question given above,
²₁H + ³₂He —> __ + ¹₁H
Let ⁿₐX be the unknown.
Thus the equation becomes:
²₁H + ³₂He —> ⁿₐX + ¹₁H
We shall determine, n, a and X. This can be obtained as follow:
For n:
2 + 3 = n + 1
5 = n + 1
Collect like terms
n = 5 – 1
n = 4
For a:
1 + 2 = a + 1
3 = a + 1
Collect like terms
a = 3 – 1
a = 2
For X:
n = 4
a = 2
X =?
ⁿₐX => ⁴₂X => ⁴₂He
Thus, the balanced equation is
²₁H + ³₂He —> ⁴₂He + ¹₁H