Question

question 1
1 pts
a 1 kg object at rest starts moving due to a 100 n force acting on it parallel to a frictionless surface. the velocity of the object at 2 m from its initial position will be:
10 m/s
20 m/s
50 m/s
100 m/s

Explanation:

Step1: Find the acceleration

According to Newton's second - law $F = ma$, where $F = 100\ N$ and $m = 1\ kg$. So $a=\frac{F}{m}=\frac{100}{1}=100\ m/s^{2}$.

Step2: Use the kinematic equation

The kinematic equation $v^{2}=v_{0}^{2}+2ax$, with $v_{0} = 0\ m/s$ (starts from rest), $a = 100\ m/s^{2}$ and $x = 2\ m$. Substitute the values: $v^{2}=0 + 2\times100\times2=400$. Then $v=\sqrt{400}=20\ m/s$.

Answer:

$20\ m/s$