Answer:
11 m/s
Explanation:
Draw a free body diagram. There are two forces acting on the car:
Weigh force mg pulling down
Normal force N pushing perpendicular to the incline
Sum the forces in the +y direction:
∑F = ma
N cos θ − mg = 0
N = mg / cos θ
Sum the forces in the radial (+x) direction:
∑F = ma
N sin θ = m v² / r
Substitute and solve for v:
(mg / cos θ) sin θ = m v² / r
g tan θ = v² / r
v = √(gr tan θ)
Plug in values:
v = √(9.8 m/s² × 48 m × tan 15°)
v = 11.2 m/s
Rounded to 2 significant figures, the maximum speed is 11 m/s.
The correct options are:
D
"Radio waves have a lower frequency, which makes them safer for humans."
B
"Radio waves take less energy to produce."
<h3>
Why do we radio waves over other electromagnetic waves to transmit information to Earth? </h3>
Radio waves are electromagnetic waves with frequencies on the range from 10 KHz to 10 THz.
Now, remember that all electromagnetic waves have the same speed, which is the speed of light, and the energy of a wave is proportional to its frequency.
Particularly, we can see that radio waves have small frequencies (smaller than infrared light) so these waves carry very little energy.
With that in mind, the correct options are.
D
"Radio waves have a lower frequency, which makes them safer for humans."
B
"Radio waves take less energy to produce."
These are the two main reasons of why we use radio waves.
If you want to learn more about electromagnetic waves.
brainly.com/question/14015797
#SPJ1
Answer:
1.
d
. A stream of particles
2. D. Radiowave
3. Microwaves
