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An object is thrown horizontally at a velocity of 18.0 m/s from the top of a cliff. If the object hit the ground 100.0 m from the base of the cliff, how high is the cliff?

a) 20.4 m
b) 40.8 m
c) 81.6 m
d) 163.2 m

User JamesStewy
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1 Answer

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Final answer:

To find the height of the cliff, we can use the equation for vertical motion. Using the given information, we can calculate the height of the cliff to be 54.4 m.

Step-by-step explanation:

To solve this problem, we can use the equations of motion. Since the object is thrown horizontally, the initial vertical velocity is zero. Therefore, we can use the equation for vertical motion to find the height of the cliff.

We know that the horizontal distance traveled by the object is 100.0 m and the initial horizontal velocity is 18.0 m/s. The equation for horizontal motion is:

distance = velocity * time

Using this equation, we can find the time it takes for the object to hit the ground. Since the initial vertical velocity is zero, the time of flight is also the time it takes for the object to hit the ground.

Now, we can use the equation for vertical motion to find the height of the cliff:

height = (1/2) * acceleration * time^2

Substituting the values we have, we get:

height = (1/2) * 9.8 m/s^2 * (2*time)

height = 9.8 m/s^2 * time

Substituting the value of time from the previous equation, we get:

height = 9.8 m/s^2 * (100.0 m / 18.0 m/s)

Simplifying the expression, we find that the height of the cliff is 54.4 m. Therefore, the correct answer is 54.4 m.

User Wojciech Kwiatek
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