Conductivity,<span>the degree to which a specified material conducts electricity, calculated as the ratio of the current density in the material to the electric field that causes the flow of current. It is the reciprocal of the resistivity.</span>
Answer:
Explanation:
Given,
- Work done by the rope 900 m/s.
- Angle of inclination of the slope =
- Initial speed of the skier = v = 1.0 m/s
- Length of the inclined surface = d = 8.0 m
part (a)
The rope is doing the work against the gravity on the skier to uplift up to the inclined surface. Therefore the work done by the rope is equal to the work done on the skier due to the gravity
In both cases the height attained by the skier is equal. and the work done by gravity does not depend upon the speed of the skier.
part (b)
- Initial speed of the skier = v = 1.0 m/s.
Rate of the work done by the rope is power of the rope.
Part (c)
- Initial speed of the skier = v = 2.0 m/s.
Rate of the work done by the rope is power of the rope.
Data:
Vo = 120 ft / s
α = 30°
t = 5 s
x = ?
Formulas:
cos(α) = Vo,x / Vo => Vo,x = Vo * cos(α)
x = Vo,x * t
Calculations:
Vo,x = 120 ft / s * cos(30) = 103.92 ft /s
x = 103.92 ft/s * 5 s = 519.6 ft
Answer: 519.6 ft
Answer:
Microwave: Radiation
Water: Conduction, convection & radiation.
Explanation:
- When we heat a food using microwave then the water content of the food is only heated by the microwave.
- Microwaves make the molecules of water vibrate frequently with a frequency closer to the frequency of microwaves and this increases the kinetic energy of the molecules which produces heat in the water molecules this heat then propagates to the whole food by conduction and convection, but the heat enters the food only via radiation.
Now when the food item is kept into warm water then the molecules closer to the food heat the food by conduction through direct energy transfer by lattice vibrations and when they become cooler than the mass of water all around then due to density difference they settle down and their place is occupied by warmer molecules around in the fluid leading to convection.
Radiation of energy from a mass occurs continuously irrespective of the medium present there. So the heat of water also enters the food by radiation of energy from the water molecules.
Answer:
Electrostatic field is a conservative field. That is work done when a charge is moved between two points is independent of path taken. Hence answer is W1