00:01
Okay, so the question was asking for the changing temperature.
00:03
Well, we know the initial speed was 865 meter per second, and the final speed is 534 meter per second.
00:10
The mass for the bullet was 15 grams, and the mass for the water is 13 .5 kilograms.
00:19
Also, we know another thing, which is the specific heat of water.
00:23
It's 4190 -0 over kilogram times kelvin.
00:30
Okay? so, well, let's take a look at the question and let me see how to do this.
00:45
Well, in order to figure out data t, we got to know q as well.
00:50
So q is unknown here.
00:52
But we can figure out q through the equation for kinetic energy, which is ke.
01:04
And how do we figure out the kinetic energy? the kinetic energy, remember it was from the bullet, the bullet was shooting from the gun and reached the water with the final speed of 534 meter per cent.
01:20
So that means the kinetic energy transfer into the heat during the process.
01:27
And due to the energy conservation law, there's no energy loss.
01:31
So basically all the kinetic energy that was burst from the bullets is converted into the heat.
01:39
In water, okay? so that's our basic idea behind this question.
01:46
Okay? so let's try to figure out the kinetic energy first, which is one -half mass of the bullet times the final speed square minus the initial speed square.
02:03
So that's the change in kinetic energy.
02:07
And let's go to the next page and they'll give us k .e.
02:12
Is equal to one -half, one -half, and then we'll give us k.
02:12
E.
02:12
Is equal to one -half, was 15 grams and 15 grand and 15 grand is equal to 15 times 10 to power 93 kilograms.
02:23
And times final speed was a6, i'm sorry.
02:31
It was 534 meter square, meter second square, okay? minus a65 meter per second square...