Answer:
3.6 KJ
Explanation: Given that a 70-kg boy is surfing and catches a wave which gives him an initial speed of 1.6 m/s. He then drops through a height of 1.60 m, and ends with a speed of 8.5 m/s. How much nonconservative work (in kJ) was done on the boy
The workdone = the energy.
There are two different energies in the scenario - the potential energy (P.E ) and the kinetic energy ( K.E )
P.E = mgh
P.E = 70 × 9.8 × 1.6
P.E = 1097.6 J
P.E = 1.098 KJ
K.E = 1/2mv^2
K.E = 1/2 × 70 × 8.5^2
K.E = 2528.75 J
K.E = 2.529 KJ
The non conservative workdone = K.E + P.E
Work done = 1.098 + 2.529
Work done = 3.63 KJ
Therefore, the non conservative workdone is 3.6 KJ approximately
Answer:
Please see answer in explanation
Explanation:
1. Since each molecule has three kinetic degrees of freedom (can move in three independent directions), the gas must have 3N DoFs.
2. Each molecule has the three kinetic degrees of freedom the monotonic atom has moving without rotating but it can also spin. There are three axes for it to spin around so we would expect three rotational degrees of freedom, but as were as above, the one about the diatomic molecule's axis doesn't count because of quantum. So we have two rotational DoFs and three kinetic, for a total of 5 per molecules. So the gas will have 5N DoFs.
3.When a spring vibrates it has two DoFs, its KE and its PE, so adding 1 vibration adds 2 DoFs per molecule, giving 7 per molecule and giving thegas 7N DoFs.
Answer:
The sea level will be 5m higher in 1667 y (years)
Explanation:
From the question, the rate at which the ocean's level is currently rising is about 3mm per year.
First, we will convert mm (millimeter) to m (meter)
1 mm = 0.001 m
Then,
3 mm = 3 × 0.001 m
= 0.003m
That is, the rate at which the ocean's level is currently rising is about 0.003m per year.
Now, to determine how long it will take for the ocean's level be 5 m higher than now at the given rate,
If the ocean rises 0.003 m in 1 year, then
the ocean will rise 5 m in x years
x = (5 m × 1 year) / 0.003 m
x = 5 / 0.003
x = 1666.67 years
x ≅ 1667 years
Hence, the sea level will be 5m higher in 1667 y (years)
