Question

7. A force of 100 N acting on a body gives it a speed of 200 m/s in 2

Answer 1

Answer:

Choice a. 1 kg, assuming that all other forces on the object (if any) are balanced.

Explanation:

By Newton's Second Law,

$\displaystyle a = \frac{\Sigma F}{m}$,

where

• $a$ is the acceleration of the object in $\text{m}\cdot\text{s}^{-2}$,
• $\Sigma F$ is the net force on the object in Newtons, and
• $m$ is the mass of the object in kilograms.

As a result,

$\displaystyle m = \frac{\Sigma F}{a}$.

Assume that all other forces on this object are balanced. The net force on the object will be $100\;\text{N}$. The net force is constant. Acceleration should also be constant and the same as the average acceleration in the two seconds.

What is the average acceleration of this object?

$\displaystyle \begin{aligned}\text{Acceleration} &= \text{Average Acceleration}=\frac{\text{Change in Velocity}}{\text{Time Taken}}\end{aligned}$.

$\displaystyle {a} = \frac{200\;\text{m}\cdot\text{s}^{-1}}{2\;\text{s}}=100\;\text{m}\cdot\text{s}^{-2}$.

Apply Newton's Second Law to find the mass of the object.

$\displaystyle m = \frac{\Sigma F}{a} = \frac{100\;\text{N}}{100\;\text{m}\cdot\text{s}^{-2}} = 1\;\text{kg}$.

Answer 2

Answer:

a.1kg

Explanation: