<span>
At the Earth's surface, warm air expands and rises, creating
what is known as an area of low pressure.
Cold air is dense and sinks to the surface to create what is
known as an area of high pressure.</span>
Answer: True!
Explanation: The force is proportional to the square of the distance between 2 point masses
Answer:
"Magnitude of a vector can be zero only if all components of a vector are zero."
Explanation:
"The magnitude of a vector can be smaller than length of one of its components."
Wrong, the magnitude of a vector is at least equal to the length of a component. This is because of the Pythagoras theorem. It can never be smaller.
"Magnitude of a vector is positive if it is directed in +x and negative if is is directed in -X direction."
False. Magnitude of a vector is always positive.
"Magnitude of a vector can be zero if only one of components is zero."
Wrong. For the magnitude of a vector to be zero, all components must be zero.
"If vector A has bigger component along x direction than vector B, it immediately means, the vector A has bigger magnitude than vector B."
Wrong. The magnitude of a vector depends on all components, not only the X component.
"Magnitude of a vector can be zero only if all components of a vector are zero."
True.
Answer:
83.3 kHz
Explanation:
The frequency of a waveform is equal to the reciprocal of its period:

where
f is the frequency
T is the period
In this problem, we have

so, the frequency of the waveform is

And by converting into kiloHertz,

Answer:
m2 = 83.3 g
Explanation:
by conservation of momentum principle we have

as both sphere has same speed so 

from conservation of kinetic energy principle we have




substituting this value in above equation to get m2 value

solving for m2 we get

m_1 = 250 g

m2 = 83.3 g