Infrared waves. The other 3 would hurt you because they are below the UV scale of 400 nanometers. Infrared is light that wouldn't harm you
Answer:
(a) 2.5 m/s
(b) 37.5 KJ
Explanation:
(a)
From the law of conservation of momentum, Initial momentum=Final momentum

and making
the subject then
and since
is initial velocity of car, value given as 4 m/s,
is the initial velocity of the three cars stuck together, value given as 2 m/s and
is the final velocity which is unknown. By substitution

(b)
Initial kinetic energy is given by

Final kinetic energy is given by

The energy lost is given by subtracting the final kinetic energy from the initial kinetic energy hence
Energy lost=350-312.5=37.5 KJ
Answer:
9.8kW
Explanation:
Given data
Mass= 60kg
Hieght= 4m
Time= 4.2seconds
We know that the energy possessed is given as
PE=mgh
PE=60*9.81*4
PE= 2354.4 Joulse
Also, the expression for power is
Power=Energy*Time
Power= 2354.4*4.2
Power=9888.48 watt
Power= 9.8kW
Answer:
Waves. Refraction is an effect that occurs when a light wave, incident at an angle away from the normal, passes a boundary from one medium into another in which there is a change in velocity of the light. ... The wavelength decreases as the light enters the medium and the light wave changes direction.
Explanation:
As a wavelength increases in size, its frequency and energy (E) decrease. From these equations you may realize that as the frequency increases, the wavelength gets shorter. ... Mechanical and electromagnetic waves with long wavelengths contain less energy than waves with short wavelengths.
<span>The atom becomes positively charged.
When you add electrons to a neutral atom, it is no longer a neutral atom, it has a negative change and is an anion. When you take away electrons from a neutral atom, it is no longer a neutral atom- it becomes a positive atom, and is a cation.</span>