<span>Our eyes can detect visible radiation, our skin can detect infra-red, our skin can also react to ultra-violet radiation by tanning, and producing skin cancers.
</span>Our brains can react directly to the impact of gamma rays ( as "seen" by astronauts )
<span>and some microwaves will cause us to heat up internally.
</span>
<span>While radio waves and ELF waves seem to ignore us totally without the aid of aerials and amplifiers. </span>
Answer:
An atomic nucleus is positively charged because it is composed of protons.
Explanation:
Protons are positively charged
Neutrons are neutral
Electrons are negatively charged
Answer: (a) 5Joules
(b) 10m/s
(c) 1.0kgm/s
(d) 33.3N
Explanation:
(a) P E = mass * gravity * height
= 0.1*10*5 = 5Joules
(b) All PE is converted to KE
Therefore;
KE = 1/2 * mass * velocity^2
5 = 1/2 * 0.1 * v^2
V = sqrt(100)
v = 10m/s
(c) change in momentum = mass * velocity
= 0.1 * 10
= 1.0kgm/s
(d) impulse = change in momentum
Change in momentum = force * time
1.0 = force * 0.03
Force = 1.0/0.03
Force = 33.3N
Therefore, the force acting on the egg is 33.3N
Answer:
a. 0.01 C
b. dissipated to outside environment
Explanation:
Let the specific heat of copper be 0.3846 kJ/kg-K or 384.6 J/kg-C
(a)The original kinetic energy of the block is:
As 85% of this kinetic energy is converted to block internal heat energy, with specific heat we can calculate the rise in temperature:
(b) the remaining 15% energy would probably be dissipated to outside environment as heat energy
Answer:
option A,B and C
Explanation:
Pangaea is known as the supercontinent which existed during the late Paleozoic and early Mesozoic eras.
Later Pangaea disintegrates into large landmass. Most of the continent include the landmass of Pangaea.
Rates of seafloor spreading in the Atlantic Ocean are known about the breakup of Pangaea.
The Appalachian Mountains are remnants of Pangaea's formation.
Hence, the correct answer is option A,B and C
