Answer:
radio waves, microwaves, infrared, visible light, ultraviolet light, X-rays, gamma rays
Explanation:
Electromagnetic waves are oscillations of electric and magnetic fields in a direction perpendicular to the direction of motion of the wave (transverse waves). They are classified into 7 different types, according to their frequencies.
From lowest to highest frequency, we have:
Radio waves 
Microwaves 
Infrared 
Visible light 
Ultraviolet 
X-rays 
Gamma rays 
Answer:
The speed of the kid and the skateboard together is 0.723 m/s
Explanation:
Let the mass of the kid be 
Let the mass of the skateboard be 
The initial speed of the skateboard, 
The initial horizontal speed of the boy as he jumps on the skateboard, 
Let the speed of the kid and the skateboard together be v
According to the principle of conservation of momentum:

Substituting the appropriate values into the given equation

36 = 49.8 v
v = 36/49.8
v = 0.723 m/s
Answer:
400kj
Explanation:
h =mass × specific heat capacity × change in temperature
= 2×2000×[120-20]
=2×2000×100
=400000j
=400kj