Answer:
They are conductors/conductive. Materials that can transfer thermal energy well are conductive.
Explanation:
Answer:
Explanation:
Given that,
Frequency of a radio antenna is 1 MHz
Power, P = 21 kW
We need to find the the waves intensity 25 km from the antenna
. The object emits intenisty evenly in all direction. It can be given by :
So, the wave intensity 25 km from the antenna is 
.
Answer:
reduction in the amount of CO₂ emissions by that household per year is 9517.2 lbm per year
Explanation:
given data
electricity consume = 14000 kWh
fuel consume = 900 gal
CO₂ produced of fuel = 26.4 lbm/gal
CO₂ produced of electricity = 1.54 lbm/kWh
oil and electricity usage = 21 percent
to find out
the reduction in the amount of CO₂ emissions
solution
we calculate the amount of CO₂ produce here that is
amount of CO₂ produce = ( electricity consume×CO₂ produce electricity + fuel consume × CO₂ consume fuel ) ........................1
put here value
amount of CO₂ produce = ( 14000 × 1.54 + 900 × 26.4 )
amount of CO₂ produce = 45320 lbm/yr
we know reduction is 21%
so
reduction in amount of CO₂ produced is
reduction in CO₂ produced = 45320 × 21%
reduction in CO₂ produced = 9517.2 lbm per year
so reduction in the amount of CO₂ emissions by that household per year is 9517.2 lbm per year
1. 0.2 g/mL
The relationship between mass, density and volume of an object is
where
d is the density
m is the mass
V is the volume
For the object in this problem, we have
m = 10 g
V = 50 mL
Substituting into the equation,
2. 10 mL
In this exercise we know:
- The density of the object: d = 2 g/mL
- The mass of the object: m = 20 g
Therefore, we can re-arrange the previous equation to find the volume:
And substituting values into the equation, we find
The previous part of the exercise says:
"<span>Engineers are designing a system by which a falling mass m imparts kinetic energy to a rotating uniform drum to which it is attached by thin, very light wire wrapped around the rim of the drum. There is no appreciable friction in the axle of the drum, and everything starts from rest. This system is being tested on Earth, but it is to be used on Mars, where the acceleration due to gravity is 3.71 m/s². In the Earth tests, when m is set to 18.0 kg and allowed to fall through 5.50 m, it gives 300.0 J of kinetic energy to the drum."
Since Kearth = Kmars, we have, for conservation of energy, that also the potential energies must be equal:
Uearth = Umars
which means:
m </span>· gearth · hearth = m · gmars <span>· hmars
we can solve for hmars:
hmars = (gearth / gmars) </span>· hearth
= (9.8 / 3.71) · 5.50
= 14.53m
Therefore, the correct answer will be: the mass would have to fall from an height of 14.53m.
