Hi there!
On a level road:
∑F = Ff (Force due to friction)
The net force is the centripetal force, so:
mv²/r = Ff
Rewrite the force due to friction:
mv²/r = μmg
Cancel out the mass:
v²/r = μg
Solve for v:
v = √rμg
v = √(25)(9.81)(0.8) = 14.01 m/s
Answer:

Explanation:
Given that,
The current in the loop, I = 2 A
The radius of the loop, r = 0.4 m
We need to find the magnetic field at a distance 0.09 m along the axis and above the center of the loop. The formula for the magnetic field at some distance is given as follows :

Put all the values,

So, the required magnetic field is equal to
.
This means that we shouldn't imagine electrons as single objects going around the atom. Instead, all we know is the probability of finding an electron at a particular location. What we end up with is something called an electron cloud. An electron cloud is an area of space in which an electron is likely to be found. It's like a 3-D graph showing the probability of finding the electron at each location in space. Quantum mechanics also tells us that a particle has certain numbers (called quantum numbers) that represent its properties. Just like how materials can be hard or soft, shiny or dull, particles have numbers to describe the properties. These include a particle's orbital quantum numbers, magnetic quantum number, and its spin. No two electrons in an atom can have exactly the same quantum numbers. Orbital quantum numbers tell you what energy level the electron is in. In the Bohr model, this represents how high the orbit is above the nucleus; higher orbits have more energy. The first orbit is n=1, the second is n=2, and so on. The magnetic quantum number is just a number that represents which direction the electron is pointing. The other important quantum mechanical property, called spin, is related to the fact that electrons come in pairs. In each pair, one electron spins one way (with a spin of one half), and the other electron spins the other way (with a spin of negative one half). Two electrons with the same spin cannot exist as a pair. This might seem kind of random, but it has effects in terms of how magnetic material is. Materials that have unpaired electrons are more likely to be magnetic
<span>speed of slower=x; distance in 6 hours is 6x
speed of larger=2x; distance in 6 hours is 12x
12x-6x=204 miles
</span><span> 6x=204
x=34 mph slower, 204 miles in 6 hours.
2x=68 mph, faster, 408 miles in 6 hours, and difference is 204 miles</span>
Answer:
7 m/s
Explanation:
To solve this problem you must use the conservation of energy.

That math speak for, initial kinetic energy plus initial potential energy equals final kinetic energy plus final potential energy.
The initial PE (potential energy) is 0 because it hasn't been raised in the air yet. The final KE (kinetic energy) is 0 because it isn't moving. This gives the following:


K1=U2

Solve for v

Input known values and you get 7 m/s.