If an object is dropped from rest near the surface of Mars, where the free-fall acceleration is $3.7 m/s^2$, what will be its velocity after falling for $4 s$?

• A. $1.85 m/s$
• B. $14.8 m/s$
• C. $3.7 m/s$
• D. $9.8 m/s$

Answer: (B)

Verified step by step guidance

1. Identify the known quantities: the initial velocity \(v_0\) is 0 m/s (since the object is dropped from rest), the acceleration due to gravity on Mars \(g\) is 3.7 m/s², and the time \(t\) the object falls is 4 s.
2. Recall the kinematic equation that relates velocity, acceleration, and time when starting from rest: \(v = v_0 + g \times t\).
3. Since the object is dropped from rest, substitute \(v_0 = 0\) into the equation, simplifying it to \(v = g \times t\).
4. Plug in the values for \(g\) and \(t\) into the equation: \(v = 3.7 \text{ m/s}^2 \times 4 \text{ s}\).
5. Calculate the product to find the velocity after 4 seconds of free fall on Mars.