Question

Nathan is walking to the store and sees a snake slithering across the sidewalk. He jumps over it with an initial vertical velocity of 10 ft/s. How long does it take for Nathan to land back on the ground

Answer 1

Answer:

$0.62\:\mathrm{s}$

Explanation:

Since the universal SI unit for velocity is meters/second, let's convert ft/s to m/s:

$10\:\mathrm{ft/s}=3.048\:\mathrm{m/s}$

We can use the following kinematics equation to solve this question:

$v_f=v_i+at$

What we know:

• The initial velocity, $v_i$, is $3.048\:\mathrm{m/s}$

• (physics concept) The final velocity must be equal in magnitude but opposite in direction to the initial velocity ($v_f=-3.048\:\mathrm{m/s}$)
• Acceleration, $a$, is acceleration due to gravity at about $9.8\:\mathrm{m/s}$

Solving for $t$:

$-3.048=3.048+(-9.8t),\\-6.096=-9.8t,\\t=\frac{-6.096}{-9.8}\approx \boxed{0.62\:\mathrm{s}}$