Answer:
The rule for kilometers is that every three seconds between a lightning flash and the following thunder gives the distance to the flash in kilometers.
Explanation:
In order to use the rule of thumb to find the speed of sound in meters per second, we need to use some conversion ratios. We know there is 1 mile per every 5 seconds after the lightning is seen. We also know that there are 5280ft in 1 mile and we also know that there are 0.3048m in 1ft. This is enough information to solve this problem. We set our conversion ratios like this:
notice how the ratios were written in such a way that the units got cancelled when calculating them. Notice that in one ratio the miles were on the numerator of the fraction while on the other they were on the denominator, which allows us to cancel them. The same happened with the feet.
The problem asks us to express the answer to one significant figure so the speed of sound rounds to 300m/s.
For the second part of the problem we need to use conversions again. This time we will write our ratios backwards and take into account that there are 1000m to 1 km, so we get:
This means that for every 3.11s there will be a distance of 1km from the place where the lightning stroke. Since this is a rule of thumb, we round to the nearest integer for the calculations to be made easily, so the rule goes like this:
The rule for kilometers is that every three seconds between a lightning flash and the following thunder gives the distance to the flash in kilometers.
Answer:
F = 10.788 N
Explanation:
Given that,
Charge 1,
Charge 2,
Distance between charges, d = 0.1 m
We know that there is a force between charges. It is called electrostatic force. It is given by :
So, the force applied between charges is 10.788 N.
Answer:
mass of the person walking to west is 65 kg.
Given:
Momentum = 52
Speed = 0.8
To find:
Mass of the person = ?
Formula used:
Momentum is given by,
P = m × v
Where, P = momentum
m = mass
v = speed
Solution:
Momentum is given by,
P = m × v
Where, P = momentum
m = mass
v = speed
Mass =
m =
m = 65 kg
Thus, mass of the person walking to west is 65 kg.
Answer:
Part A : E = ε₀ Q₁/R₁² Volt/meter
Part B : V = ε₀ Q₁/R₁ Volt
Explanation:
Given that,
Charge distributed on the sphere is Q₁
The radius of sphere is R
₁
The electric potential at infinity is 0
<em>Part A</em>
The space around a charge in which its influence is felt is known in the electric field. The strength at any point inside the electric field is defined by the force experienced by a unit positive charge placed at that point.
If a unit positive charge is placed at the surface it experiences a force according to the Coulomb law is given by
F = ε₀ Q₁/R₁²
Then the electric field at that point is
E = F/1
E = ε₀ Q₁/R₁² Volt/meter
Part B
The electric potential at a point is defined as the amount of work done in moving a unit positive charge from infinity to that point against electric forces.
Thus, the electric potential at the surface of the sphere of radius R₁ and charge distribution Q₁ is given by the relation
V = ε₀ Q₁/R₁ Volt