Answer:
The current in the circuit must be zero.
Explanation:
In a RC circuit, the steady state is reached when either the capacitor is fully charged or fully discharged. In either case, there must not be any current through the circuit because if it exists, it will deliver charge to the capacitor and thus change its charge, which is not a steady state.
Hello!
a) Assuming this is asking for the minimum speed for the rock to make the full circle, we must find the minimum speed necessary for the rock to continue moving in a circular path when it's at the top of the circle.
At the top of the circle, we have:
- Force of gravity (downward)
*Although the rock is still connected to the string, if the rock is swinging at the minimum speed required, there will be no tension in the string.
Therefore, only the force of gravity produces the net centripetal force:
![\Sigma F = F_g\\\\F_c = F_g\\\\\frac{mv^2}{r} = mg](https://tex.z-dn.net/?f=%5CSigma%20F%20%3D%20F_g%5C%5C%5C%5CF_c%20%3D%20F_g%5C%5C%5C%5C%5Cfrac%7Bmv%5E2%7D%7Br%7D%20%3D%20mg)
We can simplify and rearrange the equation to solve for 'v'.
![\frac{v^2}{r} = g\\\\v^2 = gr\\\\v = \sqrt{gr}](https://tex.z-dn.net/?f=%5Cfrac%7Bv%5E2%7D%7Br%7D%20%3D%20g%5C%5C%5C%5Cv%5E2%20%3D%20gr%5C%5C%5C%5Cv%20%3D%20%5Csqrt%7Bgr%7D)
Plugging in values:
![v = \sqrt{9.8 * 0.75} = \boxed{2.711 m/s^}](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B9.8%20%2A%200.75%7D%20%3D%20%5Cboxed%7B2.711%20m%2Fs%5E%7D)
b)
Let's do a summation of forces at the bottom of the swing. We have:
- Force due to gravity (downward, -)
- Tension force (upward, +)
The sum of these forces produces a centripetal force, upward (+).
![\Sigma F = T - F_g\\\\F_c = T - F_g\\\\\frac{mv^2}{r} = T - mg](https://tex.z-dn.net/?f=%5CSigma%20F%20%3D%20T%20-%20F_g%5C%5C%5C%5CF_c%20%3D%20T%20-%20F_g%5C%5C%5C%5C%5Cfrac%7Bmv%5E2%7D%7Br%7D%20%3D%20T%20-%20mg)
Rearranging for 'T":
![T = \frac{mv^2}{r} + mg\\\\](https://tex.z-dn.net/?f=T%20%3D%20%20%20%5Cfrac%7Bmv%5E2%7D%7Br%7D%20%2B%20%20mg%5C%5C%5C%5C)
Plugging in the appropriate values:
![T = \frac{(0.2)(2.711^2)}{(0.75)} + 0.2(9.8) = \boxed{3.92 N}](https://tex.z-dn.net/?f=T%20%3D%20%20%5Cfrac%7B%280.2%29%282.711%5E2%29%7D%7B%280.75%29%7D%20%2B%200.2%289.8%29%20%3D%20%5Cboxed%7B3.92%20N%7D)
Answer:
use hot water
Explanation:
hot water helps dissolve things faster
Answer:
<h3>30m/s</h3>
Explanation:
acceleration is the change in velocity of a body with respect to time
a = v-u/t
v is the final velocity
u is the initial velocity = 10m/s
t is the time taken = 10s
a is the acceleration = 2m/s²
substitute the values into the formula
2 = v-10/10
cross multiply
20 = v-10
v = 20+10
v = 30m/s
Hence the velocity of the body after 10s is 30m/s