Answer:
Energy conservation.
Explanation:
The 1st Law of Thermodynamics is a statement about energy conservation. It states that , which means that if we <u>substract the work W done</u> by the system to the <u>heat Q given</u> to the system we get the <u>change in the internal energy</u>
, so any excess in energy given to the system appears as internal energy, stating that energy is conserved.
Answer:
140°
Explanation:
The law of reflection states that the angle of redlection equals to the angle of incidence.
When light rays hit surface at 20°, they also leave the surface at the same angle
Since the whole surface has 180° then subtracting these two angles from total angle gives the the angle between the incident and reflected rays.
180°-20°-20°=140°
The angle of incidence and reflection are equal hence 140/2=70°
The question needed the angle between the incident and reflected rays which is already calculated as 140°
Answer:
500000N/m²
5250N
Explanation:
Given parameters:
Depth(H) = 50m
Density of water = 1000kg/m³
Acceleration of free fall = 10m/s
Unknown:
Pressure the water exerts on the diver = ?
Solution:
Pressure is the force per unit area on a body. In fluids, pressure is the product of density, gravity and height
Pressure in fluids = Density x acceleration due to gravity x height
Input the variables and solve;
Pressure in fluids = 1000 x 10 x 50 = 500000N/m²
B.
width of window = 150mm
height of window = 70mm
Force water exerts on the window = ?
To solve this problem;
Pressure =
Area of the window = width x height = 150 x 10⁻³ x 70 x 10⁻³
= 1.05 x 10 ⁻²m²
Force = pressure x area
Input the variables;
= 500000N/m² x 1.05 x 10 ⁻²m²
= 5250N