Question

question 25
a rock is kicked horizontally at a speed of 16 m/s from the edge of a cliff. the rock strikes the ground 65 m from the foot of the cliff of height h as suggested in the figure, which is not drawn to scale. neglect air resistance. how long does it take the rock to strike the ground?
11.2 s
1.0 s
1.2 s
5.5 s
4.1 s

Explanation:

Step1: Identify horizontal - motion formula

In horizontal motion (no acceleration, $a_x = 0$), the formula is $x=v_x t$, where $x$ is the horizontal displacement, $v_x$ is the horizontal velocity, and $t$ is the time.

Step2: Solve for time $t$

We know that $x = 65$ m and $v_x=16$ m/s. Rearranging the formula $t=\frac{x}{v_x}$. Substituting the values, we get $t=\frac{65}{16}=4.0625\approx4.1$ s.

Answer:

E. 4.1 s