1st Question:
There are 4 formulas involving angular velocity:
For the first question, we are given the initial angular velocity (ωo), final angular velocity (ωf), and the amount of time. The question is asking us to find the angular acceleration (α).
Knowing this information, we can use
Lets plug in the values given in the question:
Now we just solve for
Subtract 11 from each side
Divide each side by 4.5 sec.
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2nd Question:
For the second question, we want to find the change in distance (which is AKA radians). So we know we would need to use either the 1st, 3rd or the 4th equation. We are given time (t=45 s), the initial velocity (wo=0 rad/s), and the final velocity (w=245 rad/s). Since the 4th equation doesn't have time, and the 3rd equation has angular acceleration (which we weren't given), we know we will need to use the 1st equation.
(in which w is the change in velocity. Which for this case, would be 245-0)
Simplify
Answer:
31677.2 lb
Explanation:
mass of hammer (m) = 3.7 lb
initial velocity (u) = 5.8 ft/s
final velocity (v) = 0
time (t) = 0.00068 s
acceleration due to gravity (g) 32 ft/s^{2}
force = m x ( a + g )
where
- m is the mass = 3.7 lb
- g is the acceleration due to gravity = 32 ft/s^{2}
- a is the acceleration of the hammer
from v = u + at
a = (v-u)/ t
a = (0-5.8)/0.00068 = -8529.4 ( the negative sign showa the its decelerating)
we can substitute all required values into force= m x (a+g)
force = 3.7 x (8529.4 + 32) = 31677.2 lb
Answer:
dolphins and wolfs very easy
Explanation:
Answer:
a. 2865 km
Explanation:
Eratosthenes observed that the sun's rays formed a vertical angle of 7º 12 ’. Which confirmed that the Earth was not flat, assuming that it had a spherical shape, using the distance between Alexandria and Siena and the measure of the angle of inclination of the solar rays in Alexandria, calculated the circumference of the Earth.
The calculation was made with a simple rule of three:
angle of inclination of the solar rays——————- distance
360º ————- Planet circumference
And since we know that: