Answer:
coordinates of the center of mass for these two rods
(
,
)= (
,
)cm
Explanation:
given
mass of a rod = 2m
length of the rod = 3L
mass of two rods = 2(2m) = 4m
radius = diameter/2 = 
attached is the diagram and solution to the question
Answer:

Explanation:
We need to find the energy for an electron to jump from n = 1 to n = 4.
The energy in transition from 1 state to another is given by :

The difference in energy for n = 1 to n = 4 is:

So, the required energy is equal to
.
Answer:
10.4mm
Explanation:
2 pages = 1 leaf
200 pages = 100 leaves
100 × 0.10 = 10 mm thickness
Total thickness = 2(0.20) +10 = 0.4+10 = 10.4mm
Answer:
9.22 s
Explanation:
One-quarter of a turn away is 1/4 of 2π, or π/2 which is approximately 1.57 rad
Let t (seconds) be the time it takes for the child to catch up with the horse. We would have the following equation of motion for the child and the horse:
For the child: 
For the horse: 
For the child to catch up with the horse, they must cover the same angular distance within the same time t:



t = 25.05 or t = 9.22
Since we are looking for the shortest time we will pick t = 9.22 s