Answer:
The sound travelled 516 meters before bouncing off a cliff.
Explanation:
The sound is an example of mechanical wave, which means that it needs a medium to propagate itself at constant speed. The time needed to hear the echo is equal to twice the height of the canyon divided by the velocity of sound. In addition, the speed of sound through the air at a temperature of 20 ºC is approximately 344 meters per second. Then, the height of the canyon can be derived from the following kinematic formula:
(1)
Where:
- Height, measured in meters.
- Velocity of sound, measured in meters per second.
- Time, measured in seconds.
If we know that 
and 
, then the height of the canyon is:
The sound travelled 516 meters before bouncing off a cliff.
Weight = Mass * gravity
= 1470* 9.8 = 14406 N ≈ 14,400 N
Answer:
its speed when its height was half that of its starting point is 25.46 m/s
Explanation:
Given;
final speed of the roller coaster, v = 36 m/s
Applying general equation of motion;
V² = U² + 2gh
where;
V is the final speed of the roller coaster
U is the initial speed of the roller coaster = 0
h is the height attained at a given velocity
36² = 0 + (2 x 9.8)h
1296 = 19.6 h
h = 1296/19.6
h = 66.1224 m
when its height was half that of its starting point, h₂ = ¹/₂ h
h₂ = ¹/₂(66.1224 m) = 33.061 m
At h = 33.061 m, V = ?
V² = U² + 2gh
V² = 0 + 2 x 9.8 x 33.061
V² = 648
V = √648
V = 25.46 m/s
Therefore, its speed when its height was half that of its starting point is 25.46 m/s
U need to set up n solve the general eqn for simple harmonic motion:
x" = -(k/m)x
solution is x(t) = (x0)*cos(wt) + (v0/w)*sin(wt)
where w=sqrt(k/m), x0 is x-position at t=0 and v0 is vel at t=0
u already calculated f in Q.2 and w = 2*pi*f
x0 is 0 as it starts at eqm
v0 is given at 5.1
so u have x(t)
vel is given by x'(t) = (x0)*(-w)*sin(wt) + (v0/w)*w*cos(wt)
substitute t=0.32, x0=0, v0=5.1 n w in the above, u can solve for v at t=0.32.
Answer:
Red light
Explanation:
The electromagnetic spectrum classifies all the electromagnetic waves according to their wavelength/frequency. In order from shortest to longest wavelength, we have
Gamma rays
X rays
Ultraviolet
Visible light
Infrared
Microwaves
Radio waves
All of these waves are invisible to human eye, except for the "visible light" part of the spectrum. Waves in the visible light part are perceived by human as different colors, depending on their wavelength. More specifically, they appear as follows:
Violet (380-450 nm)
Blue (450-495 nm)
Green (495-570 nm)
Yellow (570-590 nm)
Orange (590-620 nm)
Red (620-750 nm)
So we see that the longest electromagnetic wave in the visible light part of the spectrum corresponds to red light.
