Answer:
Height from ground is 8 m where string will break
Explanation:
Let the string makes some angle with the vertical after some instant of time
So here we have
now by energy conservation we have
For string break down we have
Now height from the ground is given as
To develop this problem we will start from the definition of entropy as a function of total heat, temperature. This definition is mathematically described as
Here,
Q = Total Heat
T = Temperature
The total change of entropy from a cold object to a hot object is given by the relationship,
From this relationship we can realize that the change in entropy by the second law of thermodynamics will be positive. Therefore the temperature in the hot body will be higher than that of the cold body, this implies that this term will be smaller than the first, and in other words it would imply that the magnitude of the entropy 'of the hot body' will always be less than the entropy 'cold body'
Change in entropy is smaller than
Therefore the correct answer is C. Will always have a smaller magnitude than the change in entropy of the cold object
Answer:
E = 3456 J
Explanation:
The electrical energy expended in a resistor can be easily calculated by using the following formula:
where,
E = Energy Expended = ?
I = current through 5 ohm resistor = 2.4 A
R = Resistance = 5 ohms
P = Electrical Power = VI
Since,
V = IR (Ohm's Law)
Therefore,
P = (IR)(I) = I²R = (2.4 A)²(5 ohms) = 28.8 Watt
t = time taken = (2 min)(60 s/1 min) = 120 s
Therefore,
E = (28.8 Watt)(120 s)
<u>E = 3456 J</u>