Answer:
30 cm
Explanation:
From the principle of moment,
when a body is in equilibrium,
Sum of clock wise moment = sum of anti clock wise moment.
Note: That before Doug hangs the last mass, The clock wise moment is greater than the anti close wise moment.
As such the third mass will be placed before the knife edge. As shown in figure 1 on the attached file.
From the diagram,
W₁(50-30) + W₃(x-50) = W₂(80-50)
were, W₁ = m₁g = 0.4×9.8 = 3.92 N ( Where m₁ = 0.4 kg and g = 9.8 m/s²)
W₂ = m₂g =0.6×9.8 = 5.88 N ( where m₂ = 0.6 kg)
W₃ = m₃g = 0.3×9.8 = 2.94 N ( where m₃ = 0.3 kg)
Therefore,
3.92(30) + 2.94(50-x) = 5.88(30)
117.6 + 147-2.94x = 176.4
2.94x+264.6 = 176.4
-2.94x = 176.4-264.6
2.94x = 88.2
x = -88.2/-2.94
x = 30 cm
Thus the third mass must be hung 30 cm
Answer:
The mass of the cube is 420.8 kg.
Explanation:
Given that,
Length of edge = 38.9 cm
Density
We need to calculate the volume of cube
Using formula of volume
We need to calculate the mass of the cube
Using formula of density
Hence, The mass of the cube is 420.8 kg.
Answer:
Bulbs that heat a gas or a filament will heat up more than other light sources.
Explanation:
Incandescent bulbs are consist of thin wire known as filament which converts electric current into light. These filaments are made up of tungsten metal. The filaments gets hot due to the passage of electric currents which turns the bulb up. Bulb starts glowing and produce light then.
There are many ways to convert electricity into light that is why some bulbs heat up more than others. Some of then are very efficient (converts electricity to light mainly) while others are less efficient (converts electricity to light as well as produce plenty of heat).
For example:
- Incandescent Bulbs -they get hot
- Compact Fluorescent Light Bulbs - they get a little bit hot
- Light Emitting Diode (LED) - they don’t get hot
- Halogen Bulbs (halogen gas) - they get extremely hot
Answer: 55 x 9.02= 4,455.
Answer:
Microwaves
Infrared Waves
Visible Light
Explanation:
Electromagnetic waves consist of oscillating electric and magnetic field, which vibrate in a direction perpendicular to the direction of motion of the wave (for this reason, they are called transverse waves).
Electromagnetic waves are the only waves that do not need a medium to propagate: in fact, they can travel through a vacuum as well.
Electromagnetic waves are classified into 7 different types depending on their frequency. From highest to lowest frequency, they are:
Gamma rays
X-rays
Ultraviolet
Visible light
Infrared Waves
Microwaves
Radio waves
All the other options are a different type of waves, called 'mechanical waves', therefore they are not electromagnetic waves.