Answer:
Wind the long piece of thin wire around the uniform glass rod multiple times, find the length of the total diameters using the metre ruler, and divide by the number of times you wound it around the rod.
Explanation:
Since the diameter of one long piece of thin wire is too thin to be measured by a metre ruler, you can wind it multiple times and push it side by side to get a length you can measure.
For example, if you wound it around 20 times and the total length of 20 diameters of the wire side-by-side is 2.0 cm, one winding, which is the diameter would be 2.0cm ÷ 20 = 0.10cm or 1mm.
Mercury is very harmful to the average human being. the mercury can easily be released from the lamp if the lamp is knocked over and broken. mercury is also harmful if inhaled. sodium on the other hand is not harmful in any way.
Answer : The temperature when the water and pan reach thermal equilibrium short time later is, 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of aluminium = 
= specific heat of water = 
= mass of aluminum = 0.500 kg = 500 g
= mass of water = 0.250 kg = 250 g
= final temperature of mixture = ?
= initial temperature of aluminum = 
= initial temperature of water = 
Now put all the given values in the above formula, we get:


Therefore, the temperature when the water and pan reach thermal equilibrium short time later is, 
Answer:

Explanation:
A simple pendulum is a system consisting of a mass attached to a string, and oscillating in a periodic motion, back and forth, along an equilibrium position.
The period of a pendulum is the time it takes for the pendulum to complete one oscillation.
The period of a pendulum is given by the equation

where
L is the length of the pendulum
g is the acceleration due to gravity
From the formula, we see that the period of a pendulum does not depend on the mass.
Therefore, the only 2 factors affecting the period of a pendulum are:
- The length of the pendulum: the longer it is, the longer the period of oscillation
- The acceleration due to gravity: the greater it is, the shorter the period of the pendulum