Answer:
The speed of bullet is 354.2 m/s
Explanation:
initial temperature, T = 30 degree C
specific heat, c = 128 J/kg K
Latent heat, L = 24.7 x 1000 J/kg
melting point = 600 K = 327 degree C
Let the mass is m and the speed is v.
Kinetic energy = heat used to increase the temperature + Heat used to melt
![\frac{1}{2} mv^2 = m c (T' - T) + m L\\\\0.5 v^2 = 128 \times (327 - 30) + 24.7\times 1000\\\\0.5 v^2 = 38016 + 24700 \\\\0.5 v^2 = 62716\\\\v = 354.2 m/s](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20mv%5E2%20%3D%20m%20c%20%28T%27%20-%20T%29%20%2B%20m%20L%5C%5C%5C%5C0.5%20v%5E2%20%3D%20128%20%5Ctimes%20%28327%20-%2030%29%20%2B%2024.7%5Ctimes%201000%5C%5C%5C%5C0.5%20v%5E2%20%3D%2038016%20%2B%2024700%20%5C%5C%5C%5C0.5%20v%5E2%20%3D%2062716%5C%5C%5C%5Cv%20%3D%20354.2%20m%2Fs)
Answer:
yes
Explanation:
sound can only vibrate of particles.
Answer: I got an increase of 306 kJ in internal energy.
Explanation: I used the 1st Law and the sign convention to get the answer in the screenshot.
(sorry if i'm wrong)
:(
Answer:
4km
Explanation:
displacement is how far something has moved from its starting point
Answer:
<em>a. 137.5 m</em>
<em>b. 550 m</em>
Explanation:
<u>Accelerated Motion
</u>
If an object is changing its velocity at a constant rate, it has a uniformly accelerated motion. When the object is moving in one fixed axis, then the sign of the acceleration is negative if the object is braking, and positive if the object is increasing its speed.
The initial speed vo, final speed vt, acceleration a, and distance traveled x are related by the formula
![v_f^2=v_o^2+2ax](https://tex.z-dn.net/?f=v_f%5E2%3Dv_o%5E2%2B2ax)
a. The Race Car A has an initial speed of 55 m/s and it's said to stop. We must find at what distance it goes to vf=0. This means that the above formula becomes
![0=v_o^2+2ax](https://tex.z-dn.net/?f=0%3Dv_o%5E2%2B2ax)
Solving for x
![\displaystyle x=-\frac{v_o^2}{2a}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20x%3D-%5Cfrac%7Bv_o%5E2%7D%7B2a%7D)
The acceleration is
, negative because it's against the movement. Thus
![\displaystyle x=-\frac{55^2}{2\times (-11)}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20x%3D-%5Cfrac%7B55%5E2%7D%7B2%5Ctimes%20%28-11%29%7D)
b. If the car is going twice as fast (v0=110 m/s), then
![\displaystyle x=-\frac{110^2}{2\times (-11)}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20x%3D-%5Cfrac%7B110%5E2%7D%7B2%5Ctimes%20%28-11%29%7D)
![x=550\ m](https://tex.z-dn.net/?f=x%3D550%5C%20m)