A mother pushes a baby stroller 50 meters by applying 10 newtons of force. How much work was done?
Answer.- 500 joules
Answer:
Explanation:
Moving a magnet might cause a change in the magnetic field going through the solenoid. Whether or not it will change depends on the movement.
According to Faraday's law of induction a voltage is induced in a coil by a change in the magnetic flux. Magnetic flux is defined as the dot product of the magnetic field (a vector field) by the area enclosed by a loop of the coil.
![\Phi B = -\int{B} \, dA](https://tex.z-dn.net/?f=%5CPhi%20B%20%3D%20-%5Cint%7BB%7D%20%5C%2C%20dA)
The voltage is induced by the variation of the magnetic flux:
![\epsilon = -N * \frac{d \Phi B}{dt}](https://tex.z-dn.net/?f=%5Cepsilon%20%3D%20-N%20%2A%20%5Cfrac%7Bd%20%5CPhi%20B%7D%7Bdt%7D)
Where
ε: electromotive fore
N: number of turns in the coil
ΦB: magnetic flux
Moving the magnet faster would increase the rare of change of the magnetic flux, resulting in higher induced voltage.
Turning the magnet upside down would invert the direction of the magnetic field, reversing the voltage induced.
Answer:
3.75 m/s^2
Explanation:
The centripetal acceleration of an object in uniform circular motion is given by the equation:
![a=\frac{v^2}{r}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7Bv%5E2%7D%7Br%7D)
where
v is the tangential speed of the object
r is the radius of the trajectory
In this problem, r = 60 m and v = 15 m/s, therefore the centripetal acceleration of the car is
![a=\frac{(15 m/s)^2}{60 m}=3.75 m/s^2](https://tex.z-dn.net/?f=a%3D%5Cfrac%7B%2815%20m%2Fs%29%5E2%7D%7B60%20m%7D%3D3.75%20m%2Fs%5E2)
The water will get warmer until it starts to boil.
Hope this helps!
- Z
Answer:
Charge enter a 0.100 mm length of the axon is ![8.98\times 10^{-12} C](https://tex.z-dn.net/?f=8.98%5Ctimes%2010%5E%7B-12%7D%20C)
Explanation:
Electric field E at a point due to a point charge is given by
![E=k \frac{q}{r^2}](https://tex.z-dn.net/?f=E%3Dk%20%5Cfrac%7Bq%7D%7Br%5E2%7D)
where
is the constant =![9.0 \times 10^9 Nm^2 / C^2](https://tex.z-dn.net/?f=9.0%20%5Ctimes%2010%5E9%20%20Nm%5E2%20%2F%20C%5E2)
is the magnitude of point charge and
is the distance from the point charge
Charges entering one meter of axon is ![5.\times 10^{11} \times (+e)](https://tex.z-dn.net/?f=5.%5Ctimes%2010%5E%7B11%7D%20%5Ctimes%20%28%2Be%29)
Charges entering 0.100 mm of axon is ![5.\times 10^{11} \times (+e) \times (0.1 \times 10^{-3}](https://tex.z-dn.net/?f=5.%5Ctimes%2010%5E%7B11%7D%20%5Ctimes%20%28%2Be%29%20%5Ctimes%20%280.1%20%5Ctimes%2010%5E%7B-3%7D)
substituting the value of
in above equation, we get charge enter a 0.100 mm length of the axon is
![q=5.\times 10^{11} \times1.6\times 10^{-19} \times (0.1 \times 10^{-3}\\q=8.98\times 10^{-12} C](https://tex.z-dn.net/?f=q%3D5.%5Ctimes%2010%5E%7B11%7D%20%5Ctimes1.6%5Ctimes%2010%5E%7B-19%7D%20%20%5Ctimes%20%280.1%20%5Ctimes%2010%5E%7B-3%7D%5C%5Cq%3D8.98%5Ctimes%2010%5E%7B-12%7D%20C)