True.
A contact force is a force between two objects that are physically in contact with each other: an example of a contact force is the normal reaction of a table supporting a book.
A non-contact force is a force between two objects that are not physically in contact with each other: an example of non-contact force is the gravitational attraction between the Earth and the Moon.
Answer:
Explanation:
Given
mass of tin 
Also we know that
specific heat of tin 
Melting Point of Tin 
Heat required to raise the temperature of 100 gm tin is given by

where 




<span>Which is a gas at room temperature?
</span>B) nitrogen
Answer:
Yes
Explanation:
Yes, bluetooth devices work in a frequency range between 2.4 - 2.485GHz. Outside this frequency the devices will not communicate with each other correctly. This frequency equals a wavelength of around 1cm. Therefore, any change in the amplitude or wavelength would need to be in relation to each other in order to maintain the frequency in the required range for the bluetooth device to work accordingly. If one increases while the other remains the same it can easily change the frequency to outside the range.
I think the answer is A, please lmk if that is incorrect!