Answer: 3- Large cells of rising and sinking gasses
Explanation: Hotter gas coming from the radiative zone expands and rises through the convective zone. It can do this because the convective zone is cooler than the radiative zone and therefore less dense. As the gas rises, it cools and begins to sink again. As it falls down to the top of the radiative zone, it heats up and starts to rise. This process repeats, creating convection currents and the visual effect of boiling on the Sun's surface.
1. the distance between the charges is tripled
using coulomb's formula;
F=k Q1Q2/r^2.
the force is inversely proportional to the square of the distance between them.
therefore when the distance is tripled the electric force decreases.
2. the amount of one charge is doubled
from the formula the force is directly proportional to the product of the charges.Therefore when the amount of one charge is increased the electric force between them increases as well.
Answer:
b) the current and the voltage across the resistor
Explanation:
As soon as we close the switch then the current in the circuit will be zero because the inductor connected in series will not allow to change the current through it due to its inertial property
Since initial current through the inductor is zero so after connecting the key the current will still remains zero and then it will start increasing
The equation for current is given as
so as soon as the key is closed the current in the circuit is zero and hence the voltage across the resistor is also zero as we know
so correct answer will be
b) the current and the voltage across the resistor
Answer:
k= 236.29 W/mK
Explanation:
Assuming we have to find the thermal conductivity K of the metal.
which is given by the formula
k = (∆E/(A•∆t)) / (∆T/∆x)
where ∆E= energy imparted for melting= mL
L= latent heat of melting = 333.5 J
∆E = 333.5×8.55 J
∆E = 2841.4 J
A = cross-sectional area = 1.21×10^{-4} m^2
∆t =time of heating= 10×60 = 600 s
∆T = 100° C
∆x=length of the rod= 0.603 m
now substituting the values we get
k= 236.29 W/mK
Answer:
Trains stop in their own time.
Every freight train, every situation, every load is different. The distance it takes to halt a train in an emergency is based on multiple factors: the speed when the brakes are applied, the track's incline, the number of cars hooked behind the locomotives and the loading of those cars, the "brake delay" inherent in the train's hydraulic system, the friction-causing metallurgy of the wheels and tracks, the weather.
Even the engineer behind the controls can't know on any given day how long it would take to stop the train.
"There is no specific rule of thumb on that," said Greg Udolph, general manager of the Texas State Railroad, a freight and tourist line in East Texas running from Palestine to Rusk. "If the track is wet with dew it changes. Everything that can affect it does. A train takes as long to stop as it takes to stop. Sometimes it can be a mile. Sometimes it's less, sometime's it's more."
Explanation:
Hope this helps :)