Answer:
The change in the charge on the positve plate when the Teflon is inserted is +2.5 nC.
Explanation:
- It can be showed that the capacitance of a parallel-plate capacitor, can be expresssed as follows:
- Where ε, is the dielectric constant of the material that fills the space between plates.
- When this space is filled with air, ε= ε₀ = 8,85*10⁻¹² F/m.
- At the same time, the capacitance of a capacitor, by definition, is as follows:
- If we insert a Teflon slab, in such a way that fills completely the gap between the plates, all other parameters being equal, if ε = 2*ε₀, this means that C₂ = 2* C₁. = 50 pF
- As V₂=V₁ (due to the capacitor remains connected to the same battery) the charge must be the double, so Q₂ = 2* Q₁ = 5 nC.
- So, the change in the charge of the positive plate is +2.5 nC.
Answer:
Steven has to row at a speed to reach the same horizontal spot at the other side of the river is, V = 6 m/s
Explanation:
Given data,
The river flowing south at the rate, v = 3 m/s
To reach the other side directly across the river, he aims the raft, Ф = 30°
The speed of his raft across the river is given by the formula,
V = v / Sin Ф
= 3 / Sin 30°
= 6 m/s
Steven has to row at a speed to reach the same horizontal spot at the other side of the river is, V = 6 m/s
<span>Light travels Slower in a material with a higher index of refraction.
because </span><span>Water has a higher index of refraction than air and it travels slower (bends) in water
high index mean slow travel
hope it helps</span>
Let's see: frequency of cellular phone waves (GSM phones) is (800-1900 MHz). If we look at the table of the electromagnetic spectrum, we can see that this range is contained within the frequencies of the microwaves, which include waves in the range 300 MHz-300 GHz.
So, summarizing, the correct answer is "microwaves".
