Answer: A: electron shells outside a central nucleus
B: hard, indivisible sphere
C: mostly empty space
Which list of atomic model descriptions represents
the order of historical development from the earliest
to most recent?
Explanation:
3
Answer: 5,640 s (94 minutes)
Explanation:
the tangential speed of the HST is given by
(1)
where
is the length of the orbit
r is the radius of the orbit
T is the orbital period
In our problem, we know the tangential speed: 
. The radius of the orbit is the sum of the Earth's radius and the distance of the HST above Earth's surface:
So, we can re-arrange equation (1) to find the orbital period:
Dividing by 60, we get that this time corresponds to 94 minutes.
Answer:
e = 0.0898m
v = 2.07m/s
Explanation:
a) According to Hooke's law
F = ke
e is the extension
k is the spring constant
Since F = mg
mg = ke
e = mg/k
Substitute the given value
e = 1.1(9.8)/120
e = 10.78/120
e = 0.0898m
Hence it is stretched by 0.0898m from its unstrained length
2) Total Energy = PE+KE+Elastic potential
Total Energy = mgh +1/2mv²+1/2ke²
Substitute the given value
5.0= 1.1(9.8)(0.2)+1/2(1.1)v²+1/2(120)(0.0898)²
Solve for v
5.0 = 2.156+0.55v²+0.48338
5.0-2.156-0.48338= 0.55v²
2.36 =0.55v²
v² = 2.36/0.55
v² = 4.29
v ,= √4.29
v = 2.07m/s
Hence the required velocity is 9.28m/s
Answer: Current = 2 A
Explanation:
Given that an electrical power plant generates electricity with a
current I = 50 A
Potential difference V = 20 000 V
The resistance R will be achieved by Ohms law formula which state that
V = IR
But the power generated will be the product of potential difference and the current
Power P = IV
P = 50 × 20000
P = 1, 000000 W
When the transformer steps up the potential difference to 500 000 V before it is transmitted
Power is always constant.
Using the formula for power again with
V = 500000
1000000 = 500000× I
Make I the subject of formula
Current I = 1000000/500000
Current I = 2 A
