Answer:
mu = 0.56
Explanation:
The friction force is calculated by taking into account the deceleration of the car in 25m. This can be calculated by using the following formula:
![v^2=v_0^2+2ax\\](https://tex.z-dn.net/?f=v%5E2%3Dv_0%5E2%2B2ax%5C%5C)
v: final speed = 0m/s (the car stops)
v_o: initial speed in the interval of interest = 60km/h
= 60(1000m)/(3600s) = 16.66m/s
x: distance = 25m
BY doing a the subject of the formula and replace the values of v, v_o and x you obtain:
![a=\frac{v^2-v_o^2}{2x}=\frac{0m^2/s^2-(16.66m/s)^2}{2(25m)}=-5.55\frac{m}{s^2}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7Bv%5E2-v_o%5E2%7D%7B2x%7D%3D%5Cfrac%7B0m%5E2%2Fs%5E2-%2816.66m%2Fs%29%5E2%7D%7B2%2825m%29%7D%3D-5.55%5Cfrac%7Bm%7D%7Bs%5E2%7D)
with this value of a you calculate the friction force that makes this deceleration over the car. By using the Newton second's Law you obtain:
![F_f=ma=(1490kg)(5.55m/s^2)=8271.15N](https://tex.z-dn.net/?f=F_f%3Dma%3D%281490kg%29%285.55m%2Fs%5E2%29%3D8271.15N)
Furthermore, you use the relation between the friction force and the friction coefficient:
![F_f= \mu N=\mu mg\\\\\mu=\frac{F_f}{mg}=\frac{8271.15N}{(1490kg)(9.8m/s^2)}=0.56](https://tex.z-dn.net/?f=F_f%3D%20%5Cmu%20N%3D%5Cmu%20mg%5C%5C%5C%5C%5Cmu%3D%5Cfrac%7BF_f%7D%7Bmg%7D%3D%5Cfrac%7B8271.15N%7D%7B%281490kg%29%289.8m%2Fs%5E2%29%7D%3D0.56)
hence, the friction coefficient is 0.56
Answer:
We see objects in a dark room due to the emission of light photons which are sensitive to our eyes. Darkness is simply a terminology used to describe the absence of light. Visible light to human is a component of the electromagnetic spectrum. Our eyes have receptors that picks the photons which light releases
Explanation:
Answer:
Explanation:
The strengthcompassion field is proportional to the closeness of the field lines—more precisely, it is proportional to the number of lines per unit area perpendicular to the lines. The direction of the electric field is tangent to the field line at any point in space. Field lines can never cross. These pattern of lines, sometimes referred to as electric field lines, point in the direction that a positive test charge would accelerate if placed upon the line. As such, the lines are directed away from positively charged source charges and toward negatively charged source charges.
Rules for drawing electric field lines
1. Electric field lines are always drawn from High potential to
low potential.
2. Two electric field lines can never intersect each other.
3. The net electric field inside a Conductor is Zero.
4. Electric field line from a positive charge is drawn radially outwards and from a negative charge radially inwards.
5. The density of electric field lines tells the strength of the electric field at that region.
6. Electric field lines terminate Perpendicularly to the surface of a conductor.
A vector quantity has a direction and a magnitude, while a scalar has only a magnitude. You can tell if a quantity is a vector by whether or not it has a direction associated with it.
So, electric fields are vector quantity due to the fact any student can tell you that a compass is used to determine which direction is north.
Since the compass always point northward, then it has a direction and magnitude and so it is a vector quantity
The most probable reason why the magnets won't stick on the refrigerator is that the body of the refrigerator and the magnets have like poles. If both have negative or both have positive poles facing each other, they will repel. In principle, magnets are attracted to opposite poles and like poles repel.