Answer:
E = 1/2 m v^2 = 1/2 k x^2 equating KE of coyote and spring
x^2 = m v^2 / k = 10 kg * 20^2 m^2 / s^2 / 400 N / m
x^2 = 10 * 400 / 400 (kg m^3 / kg-m) = 10 m^2
x = 3.16 m
The first thing we have to do for this case is write the kinematic equationsto
vf = a * t + vo
rf = a * (t ^ 2/2) + vo * t + ro
Then, for the bolt we have:
100% of your fall:
97 = g * (t ^ 2/2)
clearing t
t = root (2 * ((97) / (9.8)))
t = 4.449260429
89% of your fall:
0.89*97 = g * (t ^ 2/2)
clearing t
t = root (2 * ((0.89 * 97) / (9.8)))
t = 4.197423894
11% of your fall
t = 4.449260429-4.197423894
t = 0.252
To know the speed when the last 11% of your fall begins, you must first know how long it took you to get there:
86.33 = g * (t ^ 2/2)
Determining t:
t = root (2 * ((86.33) / (9.8))) = <span>
4.19742389 </span>s
Then, your speed will be:
vf = (9.8) * (4.19742389) = 41.135 m / s
Speed just before reaching the ground:
The time will be:
t = 0.252 + <span>
4.197423894</span> = <span>
4.449423894</span> s
The speed is
vf = (9.8) * (4.449423894) =<span>
<span>43.603</span></span> m / s
answer
(a) t = 0.252 s
(b) 41,135 m / s
(c) 43.603 m / s
Solution :
Let us consider the Gaussian surface that is in the form of a cylinder having a radius of r and a length of A which is
.
The charged enclosed by the cylinder is given by,
(here, V =
is the volume of the cylinder)
If
is positive, then the electric field lines moves in the radial outward direction and is normal to Gaussian surface which is distributed uniformly.
Therefore, total flux through Gaussian cylinder is :


Now using Gauss' law, we get

or 
Therefore, the electric field is 
Hence, option (d) is correct.