The correct answer is: They possess high concentrations of free electrons
The main characteristic of good conductors such as metals is the presence of movable electrically charged particles, or electrons. So, when an electric current is applied to a metal, the electrons will move and allow electricity to pass through them. Materials opposite of metals, with low electron mobility are not good conductors, instead they are called insulators.
Answer:
option (A) - false
option (B) - true
option (C) - true
option (D) - true
option (E) - true
option (F) - true
Explanation:
The sound waves are mechanical waves that means they need a medium to travel.
The light waves are non mechanical waves it means they do not need a medium to travel.
Sound cannot travel trough vacuum.
Sound can travel through air and water.
Light can travel trough vacuum and in air and in water.
Answer:
354200J
Explanation:
Given parameters:
Mass of copper bushing = 8kg
Initial temperature = 25°C
Final temperature = 140°C
Unknown:
Quantity of heat required to heat this mass = ?
Solution:
The amount of heat required to heat mass from one temperature to another is given by;
H = m c Δt
where m is the mass
c is the specific heat
Δt is the change in temperature
C is a constant and for copper, its value is 385J/kg°C
Input the parameters;
H = 8 x 385 x (140 - 25) = 354200J
The best answer is D.
Stress is a force that acts on rock to change its shape or volume. Because stress is a force, it adds energy to the rock, which is stored in the rock until either the rock breaks or changes shape.
There are three kinds of stress, namely shearing, tension and compression.
Shearing- force that pushes a mass of rock in two opposite directions and can cause rock to break and slip apart or change shape.
Tension - force that pulls on the crust, stretching rock so that it becomes thinner in the middle.
Compression - force that squeezes rock until it folds or breaks
Answer: 
Explanation:
We can solve this problem using the <u>Poiseuille equation</u>:
Where:
is the Volume flow rate
is the effective radius
is the length
is the difference in pressure
is the viscosity of blood
Solving:
