Answer:
The amount of energy required is 
Explanation:
The energy required to convert the ice to steam is the sum of:
1) Energy required to raise the temperature of the ice from -20 to 0 degree Celsius.
2) Latent heat required to convert the ice into water.
3) Energy required to raise the temperature of water from 0 degrees to 100 degrees
4) Latent heat required to convert the water at 100 degrees to steam.
The amount of energy required in each process is as under
1) 
where
' is specific heat of ice =
2) Amount of heat required in phase 2 equals

3) The amount of heat required to raise the temperature of water from 0 to 100 degrees centigrade equals

where
' is specific heat of water=
4) Amount of heat required in phase 4 equals

Thus the total heat required equals 
Answer:
The relative velocity of the motorcycle to a passenger in the car is 30 km/h
Explanation:
The question relates to the principle of relative velocity and reference frames
The given parameters are;
The velocity of the motorcycle, v₁ = 120 km/h
The velocity of the car, v₂ = 90 km/h
The relative velocity of an object X with regards to another object Y is the velocity the object X will seem to be moving with to an observer in the rest frame of object Y written as
=
- 
Therefore, the relative velocity of the motorcycle to the car is
= v₁ - v₂, which give;
= 120 km/h - 90 km/h = 30 km/h
The relative velocity of the motorcycle to a passenger in the car = 30 km/h.
Answer:

Explanation:
Generally from kinematics equations we have that
Here u is the initial velocity of the rock and the value is 0 m/s given that there was no information that it was in motion before the fall
substituting 1.43 s for t and
for g we have that
=> 
The negative sign show that the displacement is in the direction of the negative y-axis
Answer:
7213.7kg/m³
Explanation:
Given parameters:
Volume of the metal chunk = 0.131m³
Mass of the metal chunk = 945kg
Unknown:
Density of the metal chunk = ?
Solution :
To solve this problem, density is the mass per unit volume. It is mathematically expressed as;
Density =
So;
Density =
= 7213.7kg/m³
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