Answer:
Explanation:
Using the first law of thermodynamics:
Where is the change in the internal energy of the system, in this case , is the heat tranferred, and is the work, with a negative sign since the work is done by the system.
From the previous equation we solve for heat, because it is the unknown variable in this problem
And replacing the known values:
The negative sign shows us that the heat is tranferred from the system into the surroundings.
Answer:
The combined velocity is 8.61 m/s.
Explanation:
Given that,
The mass of a truck, m = 2800 kg
Initial speed of truck, u = 12 m/s
The mass of a car, m' = 1100 kg
Initial speed of the car, u' = 0
We need to find the combined velocity the moment they stick together. Let it is V. Using the conservation of momentum.
So, the combined velocity is 8.61 m/s.
Answer:
Worldwide Radio Communication
Explanation:
The ionosphere is important because it is through the ionosphere that world wide radio communication is possible.
If the force were constant or increasing, we could guess that the speed of the sardines is increasing. Since the force is decreasing but staying in contact with the can, we know that the can is slowing down, so there must be friction involved.
Work is the integral of (force x distance) over the distance, which is just the area under the distance/force graph.
The integral of exp(-8x) dx that we need is (-1/8)exp(-8x) evaluated from 0.47 to 1.20 .
I get 0.00291 of a Joule ... seems like a very suspicious solution, but for an exponential integral at a cost of 5 measly points, what can you expect.
On the other hand, it's not really too unreasonable. The force is only 0.023 Newton at the beginning, and 0.000067 newton at the end, and the distance is only about 0.7 meter, so there certainly isn't a lot of work going on.
The main question we're left with after all of this is: Why sardines ? ?