Answer:
Because of the tilt of Earth on its axis, Earth's surface and atmosphere are unevenly heated by the Sun. Convection currents form in the atmosphere as warmer air rises and cooler air sinks.
Answer:
Substances can change phase—often because of a temperature change. At low temperatures, most substances are solid; as the temperature increases, they become liquid; at higher temperatures still, they become gaseous.
The process of a solid becoming a liquid is called melting. (an older term that you may see sometimes is fusion). The opposite process, a liquid becoming a solid, is called solidification. For any pure substance, the temperature at which melting occurs—known as the melting point—is a characteristic of that substance. It requires energy for a solid to melt into a liquid. Every pure substance has a certain amount of energy it needs to change from a solid to a liquid. This amount is called the enthalpy of fusion (or heat of fusion) of the substance, represented as ΔHfus. Some ΔHfus values are listed in Table 10.2 “Enthalpies of Fusion for Various Substances”; it is assumed that these values are for the melting point of the substance. Note that the unit of ΔHfus is kilojoules per mole, so we need to know the quantity of material to know how much energy is involved. The ΔHfus is always tabulated as a positive number. However, it can be used for both the melting and the solidification processes as long as you keep in mind that melting is always endothermic (so ΔH will be positive), while solidification is always exothermic (so ΔH will be negative).
Answer:
Velocity, u = 14.7 m/s
Explanation:
It is given that, a driver can probably survive an acceleration of 50 g that lasts for less than 30 ms, but in a crash with a 50 g acceleration lasting longer than 30 ms, a driver is unlikely to survive.
Let v is the highest speed that the car could have had such that the driver survived. Using a = -50 g and t = 30 ms
Using first equation of kinematics as :
In case of crash the final speed of the driver is, v = 0
u = 14.7 m/s
So, the highest speed that the car could have had such that the driver survived is 14.7 m/s. Hence, this is the required solution.
Answer:
0.875 moles solute
Explanation:
You can find the moles of the solute using the molality ratio:
Molality = moles solute / mass (kg) solution
After converting the mass to kilograms, you can plug the values into the ratio and simplify to find the moles.
1,000 g = 1 kg
350 g 1 kg
-------------- x --------------- = 0.35 kg solution
1,000 g
Molality = moles solute / mass solution
2.5 m = moles solute / 0.35 kg
0.875 = moles solute
Answer:
1867.88g
Explanation:
The density of a substance can be calculated by dividing its mass by its volume. That is;
Density = mass/volume
In this question, the density of water is given as is 0.9870 g/mL, volume of water held by the container is 64 fluid ounces.
The unit, however, must be the same in order to work.
Since; 29.57 mL = 1 fluid ounce
64 fluid ounces will be 64 × 29.57 mL
= 1892.48 mL
Using the formula above, the mass (m)= density (p) × volume (v)
Mass = 1892.48mL × 0.9870 g/mL
Mass= 1867.8776
Mass = 1867.88g
