Answer:
4.0 m/s
Explanation:
In the first part of the run, the athlete runs a distance of
at a speed of
So, the time he/she takes is
In the second part of the run, the athlete covers an additional distance of
with a speed
So, the time taken in this second part is
So, the total distance covered is
d = 300 m + 300 m = 600 m
And the total time taken
t = 100 s + 50 s = 150 s
Therefore, the average speed for the entire trip is
Answer:
A = -14.87 i ^ + 8.42 j ^ + 0 k ^
B = -25.41 i ^ -12.0 j ^ + 0 k ^
Explanation:
For this exercise let's use trigonometry by decomposing to vectors
vector A
module 17.1 with an angle of 150.5 counterclockwise.
Sin 150.5 = / A
cos 150.5 = Ax / A
A_{y} = A sin 150.5 = 17.1 sin 150.5
Aₓ = A cos 1505 = 172 cos 150.5
A_{y} = 8,420
Aₓ = -14.870
the vector is
A = -14.87 i ^ + 8.42 j ^ + 0 k ^
Vector B
= 28.1 sin 205.3
Bₓ = 28.1 cos 205.3
B_{y} = -12.009
Bₓ = -25.405
the vector is
B = -25.41 i ^ -12.0 j ^ + 0 k ^
Correct options:
- Blue light has a wavelength of 750 nm, the longest wavelength of visible light, and red has a wavelength of 500 nm. --> FALSE. It's actually the opposite: blue light has a wavelength of approx. 500 nm, while red has a wavelength of 750 nm, the longest wavelength of visible light.
- Light is electromagnetic radiation, a type of energy embodied in oscillating electric and magnetic fields. --> TRUE. Electromagntic radiation is a type of transverse waves, consisting of electric and magnetic fields oscillating perpendicularly to each other.
- The units of frequency are distance per second. --> FALSE. Frequency is measured in Hertz (Hz), which corresponds to 1/seconds (.
- The more closely spaced the waves, that is, the longer the wavelength, the more energy there is. --> FALSE. The energy of an electromagnetic wave is inversely proportional to the wavelength:
that means, the longer the wavelength, the less energy there is.
- Grass appears green because it reflects primarily the wavelength associated with green light and absorbs the others. --> TRUE. The color of the objects as we see them corresponds to the color they reflect, while all the other colors are absorbed by the object.
- Light in a vacuum travels at 3.00×108mph. --> FALSE. The units are wrong: the speed of light in a vacuum is .
- Electromagnetic radiation can be characterized by wavelength, amplitude, and frequency. --> TRUE. Wavelength is the distance between two consecutive crests, amplitude is the maximum displacement of the wave relative to the equilibrium position, frequency is the number of oscillations per second.
- The presence of a variety of wavelengths in white light is responsible for the way we perceive colors in objects. --> TRUE. White light consists of many different colors, and depending on which of them are absorbed/reflected by the objects, we perceive them in different ways.
Answer:
34.70 N
Explanation:
Given :
F~ 1 = 43 N in direction 38◦
F~ 2 = 26 N in direction −140◦
F~ 3 = 27 N in direction 110◦
Therefore,
F~x = 43 cos (38) + 26 cos (-140) + 27 cos (110)
= 43 (0.7) + 26 (-0.7) + 27 (-0.3)
= 3.8
F~y = 43 sin (38) + 26 sin (-140) + 27 sin (110)
= 43 (0.6) + 26 (-0.6) + 27 (0.9)
= 34.5
so, F~ =
= 34.70 N