Answer:
Explanation:
Let the volume of air be V. at atmospheric pressure, that is 10⁵ Pa
At 20 m below surface pressure will be
atmospheric pressure + hdg
10⁵ + 20 x 9.8 x 1000 = 2.96 x 10⁵Pa
At this pressure volume V becomes V/ 2.96
This volume will last 1/2.96 times time that is 60/2.96 = 20.27 minutes.
Answer:
Explanation:
Let m be mass of each sphere and θ be angle, string makes with vertex in equilibrium.
Let T be tension in the hanging string
T cosθ = mg ( for balancing in vertical direction )
for balancing in horizontal direction
Tsinθ = F ( F is force of repulsion between two charges sphere)
Dividing the two equations
Tanθ = F / mg
tan17 = F / (7.1 x 10⁻³ x 9.8)
F = 21.27 x 10⁻³ N
if q be charge on each sphere , force of repulsion between the two
F = k q x q / r² ( r is distance between two sphere , r = 2 x .7 x sin17 = .41 m )
21.27 x 10⁻³ = (9 X 10⁹ x q²) / .41²
q² = .3973 x 10⁻¹²
q = .63 x 10⁻⁶ C
no of electrons required = q / charge on a single electron
= .63 x 10⁻⁶ / 1.6 x 10⁻¹⁹
= .39375 x 10¹³
3.9375 x 10¹² .
The EM spectrum has no limits. Any frequency you can imagine
is the frequency of some electromagnetic radiation somewhere.
Answer:

Explanation:
<u>Elastic Potential Energy
</u>
Is the energy stored in an elastic material like a spring of constant k, in which case the energy is proportional to the square of the change of length Δx and the constant k.

Given a rubber band of a spring constant of k=5700 N/m that is holding potential energy of PE=8600 J, it's required to find the change of length under these conditions.
Solving for Δx:

Substituting:

Calculating:


The correct answer is B because isotopes have different numbers of neutrons, and neutrons are located in the nucleus
Hope this helps