Question

1. calculate the time (in seconds, rounded to the nearest whole number) required for an object dropped from rest to fall a vertical distance of 45 meters under the influence of gravity. $t = \sqrt{\frac{2h}{g}}$, $g = 9.8\\,\text{m/s}^2$

options:
1.0 s
3.0 s

1. s

22 s
clear all

Explanation:

Step1: Identify given values

We know \( h = 45 \, \text{m} \), \( g = 9.8 \, \text{m/s}^2 \), and the formula \( t=\sqrt{\frac{2h}{g}} \).

Step2: Substitute values into formula

Substitute \( h = 45 \) and \( g = 9.8 \) into the formula: \( t=\sqrt{\frac{2\times45}{9.8}}=\sqrt{\frac{90}{9.8}} \).

Step3: Calculate the value

First, calculate \( \frac{90}{9.8}\approx9.1837 \). Then, take the square root: \( t\approx\sqrt{9.1837}\approx3.03 \).

Step4: Round to nearest whole number

Rounding \( 3.03 \) to the nearest whole number gives \( 3 \).

Answer:

3.0 s