Answer:
D. x-rays
Explanation:
Lower frequency: Radio waves, microwaves and infrared have lower frequency than visible light. Shorter wavelength: Ultraviolet, x-rays and gamma rays have a shorter wavelength than visible light.
Answer:
The time taken to reach the maximum height is 3.20 seconds
Explanation:
The given parameters are;
The initial height from which the volcano erupts the lava bomb = 64.4 m
The initial upward velocity of the lava bomb = 31.4 m/s
The acceleration due to gravity, g = 9.8 m/s²
The time it takes the lava bomb to reach its maximum height, t, is given by the following kinematic equation as follows;
v = u - g·t
Where;
v = The final velocity = 0 m/s at maximum height
u = The initial velocity = 31.4 m/s
g = The acceleration due to gravity = 9.8 m/s²
t = The time taken to reach the maximum height
Substituting the values gives;
0 = 31.4 - 9.8 × t
∴ 31.4 = 9.8 × t
t = 31.4/9.8 ≈ 3.204
The time taken to reach the maximum height rounded to three significant figures = t ≈ 3.20 seconds
The author s feeling about a subject or topic, which is evidenced in word choice, is called tone.
Answer B. 112 m
Step-by-Step Explanation
initial velocity u = 20 m /s
final velocity v = 36 m /s
time taken t = 4 s
acceleration = (v - U) / t
= (36 - 20) / 4
a=4m/s2
from the formula
7-u2=2as , sis distance covered
putting the values
362-202=2×4×s
1296 - 400 = 8 x S
S= 112 m
Ox:vₓ=v₀
x=v₀t
Oy:y=h-gt²/2
|vy|=gt
tgα=|vy|/vₓ=gt/v₀=>t=v₀tgα/g
y=0=>h=gt²/2=v₀²tg²α/2g=>tgα=√(2gh/v₀²)=√(2*10*20/24²)=√(400/576)=0.83=>α=tg⁻¹0.83=39°
cosα=vₓ/v=v₀/v=>v=v₀/cosα=24/cos39°=24/0,77=31.16 m/s
Ec=mv²/2=2*31.16²/2=971.47 J=>Ec≈0.97 kJ
