Taking into account the Coulomb's Law:
![F_e = K\cdot \frac{Q_1\cdot Q_2}{d^2}](https://tex.z-dn.net/?f=F_e%20%3D%20K%5Ccdot%20%5Cfrac%7BQ_1%5Ccdot%20Q_2%7D%7Bd%5E2%7D)
If the value of Q_1 is doubled:
<span>
![F_e = K\cdot \frac{2Q_1\cdot Q_2}{d^2} = \bf 2F_e](https://tex.z-dn.net/?f=F_e%20%3D%20K%5Ccdot%20%5Cfrac%7B2Q_1%5Ccdot%20Q_2%7D%7Bd%5E2%7D%20%3D%20%5Cbf%202F_e)
The new force is two times bigger too.</span>
a) gia tốc = vf-vi / t
a = 14-10 / 20
a = 0,2ms⁻²
b) dưới dạng a = Δv / t
v = lúc
v = 0,2 × 40
v = 8ms⁻¹
như v = d / t
do đó d = vt
d = 8 × 40
d = 320m
hãy đánh dấu là trí óc nhất
Answer:
b. wavelength
Explanation:
The following quantities are used to describe a wave:
- Frequency --> it is the number of complete cycles/oscillations of the wave per second. Generally represented with
or f.
- Wavelength --> it corresponds to the distance between two successive crests (or between two successive troughs) of a wave. Generally represented with ![\lambda](https://tex.z-dn.net/?f=%5Clambda)
- Quantum number --> for a wave, the following quantity
is called quantum number of the wave
- Velocity --> the velocity of a wave is given by the product between wavelength and frequency:
![v=f\lambda](https://tex.z-dn.net/?f=v%3Df%5Clambda)
Therefore, the correct answer is b. wavelength.
Answer:
A)0.00966 N/C
B) counterclockwise direction
Explanation:
We are given;
Diameter of the metal ring; d = 4.3 cm
Radius;r = 2.15 cm = 0.021- m
Initial magnetic field, B = 1.12 T
Rate of decrease of the magnetic field;dB/dt = 0.23 T/s
Now, as a result of change in magnetic field, an emf will be induced in it. Thus, , electric field is induced and given by the formula :
∫E•dr = d/dt∫B.A •dA
This gives;
E(2πr) = dB/dt(πr²)
Gives;. 2E = dB/dt(r)
E = dB/dt × 2r
We are given;
E = 0.23 × 2(0.021)
E = 0.00966 N/C
The magnitude of the electric field induced in the ring has a magnitude of 0.00966 N/C
B) The direction of electric field will be in a counterclock wise direction when viewed by someone on the south pole of the magnet
Answer:
Explanation:
Glass is much more likely to break on the cement floor compared to the carpeted floor. In case of cement change in velocity occurs at a faster rate compared to the carpeted floor, so deceleration is more on the cemented floor.
As the Carpeted floor is not rigid so it takes more time to stop the glass that is why chances of breaking are less on the carpeted floor.