Velocity ratio is also defined as the ratio of a distance through which any part of a machine moves, to that which the driving part moves during the same time. An object has a mechanical advantage if it exerts a force higher than the velocity ratio.
Answer:
Explanation:
Given:
- moment of inertia of the skater with extended arms,
- moment of inertia of the the skater with pulled-in arms,
- angular velocity of the skater with extended arms,
<u>Using the law of conservation of angular momentum:</u>
Answer:
a) 0 V
b) 10 turns
c) 4000 turns
d) 12.5 A
e) 400 W
f) 0.5 A
g) 95.4%
Explanation:
A
0
B
To solve this, we would be using the simple relationship between voltage and number of turns
V1/V2 = N1/N2
500/25 = 200/N2
20 = 200/N2
N2 = 200/20
N2 = 10 turns
C
Here also, we would be using the relationship between current and the number of turns
I1/I2 = N2/N1
500/25 = N2/20
20 = N2/20
N2 = 20 * 20
N2 = 4000 turns
D
Like in the previous question, current and the number of turn relationship is used
N1/N2 = I2/I1
400/80 = I2/2.5
5 = I2/2.5
I2 = 5 * 2.5
I2 = 12.5 A
E
The power remains unchanged at 400 W
F
Power = Voltage * Current
P = VI
I = P/V
I = 60/120
I = 0.5 A
G
95.4%
Answer:
Explanation:
Satellites experiment a force given by Newton's Gravitation Law:
where M is Earth's mass, m the satellite's mass, r the distance between their gravitational centers and G the gravitational constant.
We also know from Newton's 2nd Law that <em>F=ma, </em>so putting both together we will have:
If we are on the surface of the Earth, the acceleration would be g and (Earth's radius):
Which we will write as:
If we are on orbit the acceleration is centripetal (), so we have:
And if this orbit has a radius we have: