Answer:
V2 = 15.53 [m/s]]
Explanation:
In order to solve this problem we must use the principle of energy conservation, where potential energy is transformed into kinetic energy. At the bottom is taken as a reference level of potential energy, where the value of this energy is equal to zero.
Above the inclined plane we have two energies, kinetics and potential. While when the sled is at the reference level all this energy will have been transformed into kinetic energy.
![E_{1}=E_{2}\\ m*g*h+(\frac{1}{2} )*m*v_{1} ^{2}=\frac{1}{2}*m*v_{2} ^{2} \\(9.81*8.21)+(0.5*8.96^{2} )=(0.5*v_{2}^{2} )\\(0.5*v_{2}^{2} )=120.68\\v_{2} ^{2}=241.36\\v_{2} =\sqrt{241.36}\\ v_{2} =15.53[m/s]](https://tex.z-dn.net/?f=E_%7B1%7D%3DE_%7B2%7D%5C%5C%20%20m%2Ag%2Ah%2B%28%5Cfrac%7B1%7D%7B2%7D%20%29%2Am%2Av_%7B1%7D%20%5E%7B2%7D%3D%5Cfrac%7B1%7D%7B2%7D%2Am%2Av_%7B2%7D%20%5E%7B2%7D%20%5C%5C%289.81%2A8.21%29%2B%280.5%2A8.96%5E%7B2%7D%20%29%3D%280.5%2Av_%7B2%7D%5E%7B2%7D%20%29%5C%5C%280.5%2Av_%7B2%7D%5E%7B2%7D%20%29%3D120.68%5C%5Cv_%7B2%7D%20%5E%7B2%7D%3D241.36%5C%5Cv_%7B2%7D%20%3D%5Csqrt%7B241.36%7D%5C%5C%20%20v_%7B2%7D%20%3D15.53%5Bm%2Fs%5D)
I'm pretty sure that its A. collapse of an Interstellar cloud.
Answer:
1.06 secs
Explanation:
Initial speed of sled, u = 8.4 m/s
Final speed of sled, v = 5.8 m/s
Coefficient of kinetic friction, μ = 0.25
Using the impulse momentum theory, we know that the impulse applied to the sled is equal to change in momentum of the sled:
FΔt = mv - mu
where m = mass of the object
Δt = time interval
F = force applied
The force applied on the sled is the frictional force, which is given as:
F = -μmg
where g = acceleration due to gravity
Therefore:
-μmgΔt = mv - mu
-μmgΔt = m(v - u)
-μgΔt = v - u
Making Δt subject of formula:
Δt = (v - u) / -μg
Δt = (5.8 - 8.4) / (-0.25 * 9.8)
Δt = -2.6/ -2.45
Δt = 1.06 secs
It took the sled 1.06 secs to travel from A to B.
Answer:
Focal length, f = 0.43 meters
Explanation:
It is given that,
Power of the reading glasses, P = 2.3 D
We need to calculate the focal length of the reading glasses. The relationship between the power and the focal length inverse i.e.
f = 0.43 m
So, the focal length of the reading glasses found on the rack in a drugstore is 0.43 meters.
