Answer:

Explanation:
given,
length of ladder = 10 ft
let x be the distance of the bottom and y be the distance of the top of ladder.
x² + y² = 100
differentiating with respect to time we get
..............(1)
when x = 8 and y = 6 and when \dfrac{dx}{dt} = 1.4ft/s
from equation (1)
now,


let the angle between the ladders be θ

y = xtan θ




Answer:

Explanation:
We need to find the energy for an electron to jump from n = 1 to n = 4.
The energy in transition from 1 state to another is given by :

The difference in energy for n = 1 to n = 4 is:

So, the required energy is equal to
.
Answer:
I think the awnser is B (but don't qoute me on that) if its right then yay but if its wrong im sorry
Explanation:
The formula for the mass that remains:

m₀ - the initial mass, t - time, T - the half-life

The answer is c. 1.25 g.