Answer:
15
Explanation:
The mass number is defined as the total number of protons and neutrons. The atomic number is total number of protons. And since we have the mass number and number of neutrons, we can use simple subtraction (30 - 15) to find that the atomic number is 15.
All the 4 processes are correct answer to change the state of matter. Hope it helps.
The basic relationship between mass m, volume V and density d is given by

re-arranging the equations and using m=1 kg and

, we find the volume:

and since

, this corresponds to

of air.
Answer:
1. 0.57 m/s
2. 25 Watts
Explanation:
1. Determination of the speed.
We'll begin by converting 1.5 hp to watt (W). This can be obtained as follow:
1 hp = 745.7 W
Therefore,
1.5 hp = 1.5 hp × 745.7 W / 1 hp
1.5 hp = 1118.55 W
Next, we shall determine the force. This can be obtained as follow:
Mass (m) = 200 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Force (F) =?
F = m × g
F = 200 × 9.8
F = 1960 N
Finally, we shall determine the speed. This can be obtained as follow:
Power (P) = 1118.55 W
Force (F) = 1960 N
Speed (v) =?
P = F × v
1118.55 = 1960 × v
Divide both side by 1960
v = 1118.55 / 1960
v = 0.57 m/s
Thus, the speed is 0.57 m/s
2. Determination of the power.
We'll begin by calculating the velocity. This can be obtained as follow:
Displacement = 10 m up
Time = 20 s
Velocity =?
Velocity = Displacement / time
Velocity = 10 / 20
Velocity = 0.5 m/s
Finally, we shall determine the power. This can be obtained as follow:
Velocity (v) = 0.5 m/s
Force (F) = 50 N
Power (P) =?
P = F × v
P = 50 × 0.5
P = 25 Watts
Therefore, the power required to lift the bucket is 25 Watts