Answer:
B. Radiowaves
Explanation:
Radiowaves are on the higher end of the spectrum, then infrared, visible light, and UV light (which is the lowest energy)
Answer:
t = o.6 s
Explanation:
Let ball thrown from below be A and ball dropped from above be B.
A and B meet when they both are same level above the ground. Then let A moved up a distance d and B dropped a distance h. Then you know
d + h = 15 m ---------------(1)
Now apply s = ut + 
at²
To A upwards,
d = 25t - gt² -----------------(2)
To B downwards,
h = 0 + gt² ----------------(3)
(1) = (2) + (3) ⇒ 15 = 25t
t = 0.6 s
True, all of those careers go in the same category
Answer:
(a) 5.7 s
(b) 39 m/s
Explanation:
(a) u = 18 m/s
At the maximum height, the final velocity of ball is zero. lte teh time taken by the ball to go from 50 m height to maximum height is t.
use first equation of motion.
v = u + g t
0 = 18 - 10 x t
t = 1.8 s
Let the maximum height attained by the ball when it thrown from 50 m height is h'.
Use third equation of motion
v^2 = u^2 + 2 g h'
0 = 18^2 - 2 x 10 x h'
h' = 16.2 m
Total height from the ground H = h + h' = 50 + 16.2 = 76.2 m
Let t' be the time taken by the ball to hit the ground as it falls from maximum height.
use third equation of motion
H = ut + 1/2 x g t'^2
76.2 = 0 + 1/2 x 10 x t'^2
t' = 3.9 s
Total time taken by the ball to hit the ground = T = t + t' = 1.8 + 3.9 = 5.7 s
(b) Let v be the velocity with which the ball strikes the ground.
v^2 = u^2 + 2 g H
v^2 = 0 + 2 x 10 x 76.2
v = 39 m/s
