Answer:
The Doppler red-shift of light observed from distant stars and galaxies gives evidence that the universe is expanding (moving away from a central point). This allows for Big Bang Theory, because after a “bang” occurs all of the matter moves away from the point of origin.
Answer:
30 seconds
Explanation:
A = A02^-(t/hl)
--> ln(A/A0) = -(t/hl)ln2
solving for hl,
hl = -t x ln2 /ln(A/A0)
= -(60 min)xln2/ln(50/200)
= 0.5 min or 30 seconds
Answer:
The tension in the string is equal to Ct
And the time t0 when the rension in the string is 27N is 3.6s.
Explanation:
An approach to solving this problem jnvolves looking at the whole system as one body by drawing an imaginary box around both bodies and taking summation of the forces. This gives F2 - F1 = Ct. This is only possible assuming the string is massless and does not stretch, that way transmitting the force applied across it undiminished.
So T = Ct
When T = 27N then t = T/C = 27/7.5 = 3.6s