Lower frequency waves have less strength to penetrate. How bad a wave is all depends on how well it penetrates our bodies. Visible light doesn't penetrate ur skin, but UV rays (higher than visible) can go through our skin, making it <span>bad" for us. High frequency waves have more energy and move faster</span>
Answer:
I'm not sure, My best friend knows, but I don't...
Explanation:
I'm sorry :)
Answer:
Explanation:
radius of circle r = 0.9 m.
(a ) In a motion on circular path , work done is zero because force ( centripetal force ) acts perpendicular to displacement .
( b )
Tension in string T = m ω²r
Putting the values
60 = .072 x ω² x 0.9
ω² = 926
ω = 30.4 rad /s
angle made in 20 revolutions θ = 20 x 2π = 126.6 rad
time taken = θ / ω
= 126.6 / 30.4
= 4.16 s .
Answer:
D
Explanation:
The decrease in potential energy is equal to the increase in kinetic energy.
mgh
250 x 9.8 x 30
=73, 500
Answer:
8 seconds
Explanation:
From Newton's second law;
Ft = m(v-u)
F = Force applied
t = time taken
v = final velocity
u = initial velocity
20 * t = 32 (9 - 4)
20t = 32 * 5
t = 32 * 5/ 20
t = 8 seconds
