B. Ptolemy believed that the earth was the center of the universe
Answer: b
Explanation:
When heat is released by the system i.e. system loses heat. So, we take it as negative -Q
When the work is done on the system then it is considered as negative work on the system i.e. -W
In this case, the plunger is pulled out, and work is done on the system. So, we take work as negative work -W
Correct option is b
Work done by a given force is given by

here on sled two forces will do work
1. Applied force by Max
2. Frictional force due to ground
Now by force diagram of sled we can see the angle of force and displacement
work done by Max = 

Now similarly work done by frictional force



Now total work done on sled


Answer:
the speed of the waves is 150 cm/s
Explanation:
Given;
frequency of the wave, f = 10 Hz = 10
distance between 4 nodes, L = 15.0 cm
The wavelength (λ) of the wave is calculated as follows;
Node to Node = λ/2
L = 2(Node to Node) = (4 Nodes) = 2 (λ/2) = λ
Thus, λ = L = 15.0 cm
The speed (v) of the wave is calculated as follows;
v = fλ
v = 10 Hz x 15.0 cm
v = 150 cm/s
Therefore, the speed of the waves is 150 cm/s
Answer:
The phenomenon known as "tunneling" is one of the best-known predictions of quantum physics, because it so dramatically confounds our classical intuition for how objects ought to behave. If you create a narrow region of space that a particle would have to have a relatively high energy to enter, classical reasoning tells us that low-energy particles heading toward that region should reflect off the boundary with 100% probability. Instead, there is a tiny chance of finding those particles on the far side of the region, with no loss of energy. It's as if they simply evaded the "barrier" region by making a "tunnel" through it.
Explanation: