IMA = Ideal Mechanical Advantage
First class lever = > F1 * x2 = F2 * x1
Where F1 is the force applied to beat F2. The distance from F1 and the pivot is x1 and the distance from F2 and the pivot is x2
=> F1/F2 = x1 /x2
IMA = F1/F2 = x1/x2
Now you can see the effects of changing F1, F2, x1 and x2.
If you decrease the lengt X1 between the applied effort (F1) and the pivot, IMA decreases.
If you increase the length X1 between the applied effort (F1) and the pivot, IMA increases.
If you decrease the applied effort (F1) and increase the distance between it and the pivot (X1) the new IMA may incrase or decrase depending on the ratio of the changes.
If you decrease the applied effort (F1) and decrease the distance between it and the pivot (X1) IMA will decrease.
Answer: Increase the length between the applied effort and the pivot.
Answer:
I think it is the last one.
Explanation:
I am not sure because i am stuck on this one, too.
Answer:
(a) Vf = 128 ft/s
(b) K.E = 122.8 Btu
Explanation:
(a)
In order to find the velocity of the object just before striking the surface of earth or the final velocity, we use 3rd equation of motion:
2gh = Vf² - Vi²
where,
g = 32.2 ft/s²
h = height = 253 ft
Vf = Final Velocity = ?
Vi = Initial Velocity = 10 ft/s
Therefore,
(2)(32.2 ft/s²)(253 ft) = Vf² - (10 ft/s)²
16293.2 ft²/s² + 100 ft²/s² = Vf²
Vf = √(16393.2 ft²/s²)
<u>Vf = 128 ft/s</u>
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(b)
The kinetic energy of the object before it hits the surface of earth is given by:
K.E = (0.5)(m)(Vf)²
where,
m = mass of object = 375 lb
K.E = Kinetic energy of object before it strikes the surface of earth = ?
Therefore,
K.E = (0.5)(375 lb)(128 ft/s)²
K.E = 3073725 lb.ft²/s²
Now, converting this to Btu:
K.E = (3073725 lb.ft²/s²)(1 Btu/25037 lb.ft²/s²)
<u>K.E = 122.8 Btu</u>
Explanation:
<u>Formula:</u>

<u>d = distance given</u>
<u>t</u><u> </u><u>=</u><u> </u><u>the amount of time </u><u>given</u>
<u>Substitute the given values into the formula for velocity</u><u>:</u>

velocity is shortened for v.
8 (distance) divided by 4 (time) equals the velocity.
<u>Solve:</u>

The velocity of the toy car equals: B. 2 m/s.