The faster car behind is catching up/closing the gap/gaining on
the slow truck in front at the rate of (90 - 50) = 40 km/hr.
At that rate, it takes (100 m) / (40,000 m/hr) = 1/400 of an hour
to reach the truck.
(1/400 hour) x (3,600 seconds/hour) = 3600/400 = <em>9 seconds</em>, exactly
To answer the problem we would be using this formula which isE = hc/L where E is the energy, h is Planck's constant, c is the speed of light and L is the wavelength
L = hc/E = 4.136×10−15 eV·s (2.998x10^8 m/s)/10^4 eV
= 1.240x10^-10 m
= 1.240x10^-1 nm
Answer:
a = 7.5 m / s²
Explanation:
For this exercise let's use Newton's second law, let's create a coordinate system with the x axis parallel to the plane and the y axis perpendicular to the plane
Y axis
N - W cos θ = 0
N = mg cos θ
X axis
W sin θ = m a
mg sin θ = m a
a = g sin θ
let's calculate
a = 9.8 cos 40
a = 7.5 m / s²
To solve the problem we will simply perform equivalence between both expressions. We will proceed to place your units and develop your internal operations in case there is any. From there we will compare and look at its consistency
At the same time we have that
Therefore there is not have same units and both are not consistent and the correct answer is B.
Light that enters the new medium <em>perpendicular to the surface</em> keeps sailing straight through the new medium unrefracted (in the same direction).
Perpendicular to the surface is the "normal" to the surface. So the angle of incidence (angle between the laser and the normal) is zero, and the law of refraction (just like the law of reflection) predicts an angle of zero between the normal and the refracted (or the reflected) beam.
Moral of the story: If you want your laser to keep going in the same direction after it enters the water, or to bounce back in the same direction it came from when it hits the mirror, then shoot it <em>straight on</em> to the surface, perpendicular to it.
