Hello!
===
When objects are heated, their molecules tend to vibrate fast. As they vibrate, the space between each atom increases. This keeps on happening, and the object expands until it has cooled down.
===
Hope this helps! :)
Answer:
2.8 cm
Explanation:
= Separation between two first order diffraction minima = 1.4 cm
D = Distance of screen = 1.2 m
m = Order
Fringe width is given by

Fringe width is also given by

For second order

Distance between two second order minima is given by


The distance between the two second order minima is 2.8 cm
The answer is (A) hope it helps
Answer:

Explanation:
The acceleration of an object is given by Newton's second law:

where
F is the net force applied on the object
m is the mass of the object
For the book in the problem, we have:
is the mass
is the force applied
Substituting into the formula, we find the acceleration:

If I remember correctly, it is the 3rd answer choice.