Answer:
Part 1)

Part 2)

Part 3)

Part 4)
Since torque on right side is more so here it will turn and slip over it
Explanation:
As we know that the block A is placed at distance
d = 50 cm from the hinge at 70 cm mark
So torque due to weight of A is given as

the block B is placed at distance
d = 30 cm from the hinge at 70 cm mark
So torque due to weight of B is given as

Now torque due to weight of the scale is given as


now torque on left side of scale is given as


Torque on right Side is given as

Since torque on right side is more so here it will turn and slip over it
Answer:
a) Yes
b) No
Explanation:
In the first case, part a, yes we can say for certainty that cylinderical symmetry holds. Why so? You may ask. This is because from the question, we are told that the length of the rod is 300 cm. And this said length is longer than the distance to the point from the center of the rod, which is 5 cm.
In the second half of the question, I beg to disagree that cylindrical symmetry holds. Again, you may ask why, this is because the length of the rod in this case, is having the same order of magnitude as the distance to the center of the rod. Thus, it is not symmetrical.
Answer:
A. False, frequency can increase or decrease wavelength.
For example: a high frequency would mean there are shorter wavelengths that occur in a period. Meanwhile, a low frequency would indicate that the wavelengths are longer and in longer periods.
Answer:
A) Its density will decrease
Explanation:
When an object is heated, its volume increases. This is due to the fact that the particles in the medium vibrate more (if it is a solid) or they move more (if it is a liquid or a gas), therefore they tend to occupy a larger space.
At the same time, the mass of the object does not change, because the mass just represents the amount of matter contained in the object, so it does not increase/decrease at different temperatures.
The density of an object is defined as the ratio between the mass (m) and the volume (V):

We said that the mass remains unchanged while the volume increases: since the density is inversely proportional to the volume, this means that the density decreases.