Answer:
Oil : about 50years
Gas: about 52years
Coal: about 114years
Explanation:
Oil
Globally, we currently consume the equivalent of over 11 billion tonnes of oil from fossil fuels every year. Crude oil reserves are vanishing at a rate of more than 4 billion tonnes a year, so if we carry on as we are, our known oil deposits could run out in just about 50 years.
Gas
If we increase gas production to fill the energy gap left by oil, our known gas reserves only give us just 52 years left.
Coal
Although it’s often claimed that we have enough coal to last hundreds of years, this doesn’t take into account the need for increased production if we run out of oil and gas.
If we step up production to make up for depleted oil and gas reserves, our known coal deposits could be gone in 114 years.
Answer:
Explanation:
charge transferred to sphere = 12 - 8 = 4 nC
a )
The positive charge is decreased on glass rod , that means electrons must have entered the glass rod from the sphere which reduces its positive charge.
b )
charge transferred = 4 nC = 4 x 10⁻⁹ C
charge on one electron = 1.6 x 10⁻¹⁹ C
No of electrons transferred
= Total charge transferred / charge on one electron
= 4 x 10⁻⁹ / 1.6 x 10⁻¹⁹
= 2.5 x 10¹⁰ .
Answer:
moving the boxes and the furniture up to the fifth floor.
Explanation:
The work done when moving an object up or down is equal to its change of gravitational potential energy:
where
m is the mass of the object
g is the gravitational acceleration
is the change in height of the object
We have two opposite situations:
1) when an object is moved upward, is positive, so the work done W is positive as well: this means that we need to do work in order to move the object, because we have to "win" the effect of gravity, which pulls the object downward
2) when an object is moved downward, is negative, so the work done W is negative as well: this means that we do not need to do work on the object, because it is already done by gravity, which pulls the object downward.
Therefore, more work is done when we are moving the boxes and the furniture up to the fifth floor.
Explanation:
When there is a sudden temperature change after a calm and cloudy weather then it is most probably due to the low pressure at the site. When there develops a low pressure at a site then to counter balance it the air from the high pressure area moves to the low pressure area and the moisture in the air also gets carried along to the mountainous cold region.
When the moist air flows over a cold region then the moisture of the air condenses and the atmosphere becomes cloudy and foggy with large quantity of precipitation.
