700 J is the work done by the system.
<u>Explanation:</u>
The first law of thermodynamics is that the change in internal energy of the system is equal to the net heat transfer to the system minus the complete work performed by the system.
Where,
∆U – Change in internal energy
Q – Heat transfer to the system
Q – Work done
Here,
<u>Given data:</u>
∆U - 400 J
Q - 1100 J
We need to the work done by the system (W)
By applying the given values in the above equation, we get
400 = 1100 - W
W = 1100 - 400 = 700 J
Answer:
Option (b).
Explanation:
Mass of an object is defined as the amount of matter contained in it. In this case, the mass of helium gas in a balloon is the amount of matter inside the balloon. It is independent of the outside condition.
Hence, out of 4 options, the correct option is (b).
Answer: Newton's law of gravity theory disagrees with Einstein's theory. The last one were named Theory of General Relativity and was discovered and proposed by the physicist Einstein in the year of 1915.
Explanation: Until the beginning of 20 century, the physics were ruled by Isaac Newton's ideas. He believed that the gravity was a force caused by the objects mass on the space, made them to be draw towards each other. Newton thought that the greater the mass of the object, the more intense was its attraction, which would justify the planet's moovements around the sun and how the gravity between them maintain the planets on solar orbit. Concluding, he believed gravity was a immediate force of action, regardless of the distance of the bodies.
Contrary to Newton's law of gravity, in 1915, the physicist Einstein created the Theory of General Relativity, wich discovered that gravity was, in fact, the deformation caused by the attraction of massive celestial bodies. This deformation, related to the Sun, for example, creates a curvature on the space-time and this curvature are followed by the other planets.
So, we can conclude that Newton's law of gravity disagree's with the Theory of General Relativity, once the first believes that light force of attraction are transmitted instantly and, as Einstein already prooved, the gravity influency propagates in the speed of light.
Answer:
Series circuit
Explanation:
By definition series circuit is a closed circuit in which the flow of electric current follows only one path.
In a simple electrical circuit (which is a series circuit) where electric cell is the source of power, each component is connected in such a way that there is only one pathway current flows from the positive terminal(+) round to the negative terminal(-) via the external circuit.
Current having only one pathway to flow means that when one of the components is removed, there will be no current flow.
Answer:
The tension T in each of the cables, T = 98 N
Explanation:
Given,
The mass of the loudspeaker, m = 20.0 Kg
The suspended distance of the loudspeaker, d = 2.20 m
The length of each cable, l = 2.9 m
The tension experienced by the cable is given by the formula,
T = mg + ma newton
Where,
g - acceleration due to gravity
a-acceleration produced by the stretched cable
Since the stretched cable and loudspeaker is not moving, then the tension force acting on the cable is equal to the force of gravity.
T = mg newton
Substituting the values in the above equation
T = 20
= 20.0 Kg x 9.8 m/s²
= 196 N
This force is equally supported by the two cables, then the tension in each cable is
T = 196 N / 2
= 98 N
Hence, the tension T in each of the cables, T = 98 N
