Question

An object falls 210 m in 6.3 s. What was it's initial velocity? Express your answer with the correct number of significant digits.

Answer 1

Answer:

$u = 2.5 \ m/s$

Explanation:

Given data:

Height, $h = 210 \ m$

Time, $t = 6.3 \ s$

Let the initial velocity of the object be u.

From the kinematic equation,

$h = ut + \frac{1}{2}gt^{2}$

$210 = u \times 6.3 + 0.5 \times 9.80 \times (6.3)^{2}$

$\Rightarrow \ u = 2.46 \ m/s$

$u = 2.5 \ m/s$ (rounding to tenth place)