Multiple-Concept Example 4 deals with a situation similar to that presented here. A marble is thrown horizontally with a speed o
f 17.1 m/s from the top of a building. When it strikes the ground, the marble has a velocity that makes an angle of 39 ° with the horizontal. From what height above the ground was the marble thrown?
1 answer:
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Answer:
The answer is 2,416 m/s. Let's jump in.
Explanation:
We do work with the amount of energy we can transfer to objects. According to energy theory:
W = ΔE
Also as we know W = F.x
We choose our reference point as a horizontal line at the block's rest point.<u> At the rest, block doesn't have kinetic energy</u> and <u>since it is on the reference point(as we decided) it also has no potential energy.</u>
Under the force block gains;
W = F.x →
In the second position block has both kinetic and potential energy. Following the law of conservation of energy;
W = ΔE = Kinetic energy + Potantial Energy
W = ΔE =
Here we can find h in the triangle i draw in the picture using sine theorem;
In a triangle
In our situation
→
Therefore
→
