Answer: These are the starting of than energy i think chemical, electrical, radiant, mechanical, thermal
Answer:
The time taken is 
Explanation:
From the question we are told that
The speed is 
The length of the tennis court 
Generally the time taken is mathematically represented as

=> 
Explanation:
q = mCΔT
where q is heat,
m is mass,
C is specific heat capacity,
and ΔT is temperature change.
For the first ball:
2500 J = (100 g) C (90°C − 25°C)
C = 0.385 J/g/°C
For the second ball:
5000 J = (200 g) C (90°C − 25°C)
C = 0.385 J/g/°C
The two metals have the same specific heat, and are likely the same metal (possibly copper or zinc).
Answer:
a) L = 33.369 m
, b) 21
Explanation:
The analysis of the ocean depth can be performed assuming that at the bottom of the ocean there is a node and the surface must have a belly, so the expression for resonance is
λ = 4 L / n
n = 1, 3, 5, ...
The speed of the wave is
v = λ f
v = 4L / n f
L = n v / 4f
Let's write the expression for the two frequencies
L = n₁ 343/4 53.95
L = n₁ 1,589
L = n₂ 343/4 59
L = n₂ 1.4539
Let's solve the two equations
n₁ 1,589 = n₂ 1,459
n₁ / n₂ = 1.4539 / 1.589
n₁ / n2 = 0.91498
Since the two frequencies are very close the whole numbers must be of consecutive resonances, let's test what values give this value
n₁ n₂ n₁ / n₂
1 3 0.3
3 5 0.6
5 7 0.7
7 9 0.77
9 11 0.8
17 19 0.89
19 21 0.905
21 23 0.913
23 25 0.92
Therefore the relation of the nodes is n₁ = 21 and n₂ = 23
Let's calculate
L = n₁ 1,589
L = 21 1,589
L = 33.369 m
b) the number of node and nodes is equal therefore there are 21 antinode
The first: alright, first: you draw the person in the elevator, then draw a red arrow, pointing downwards, beginning from his center of mass. This arrow is representing the gravitational force, Fg.
You can always calculate this right away, if you know his mass, by multiplying his weight in kg by the gravitational constant

let's do it for this case:

the unit of your fg will be in Newton [N]
so, first step solved, Fg is 637.65N
Fg is a field force by the way, and at the same time, the elevator is pushing up on him with 637.65N, so you draw another arrow pointing upwards, ending at the tip of the downwards arrow.
now let's calculate the force of the elevator

so you draw another arrow which is pointing downwards on him, because the elevator is accelating him upwards, making him heavier
the elevator force in this case is a contact force, because it only comes to existence while the two are touching, while Fg is the same everywhere