Question

The force required to stop a body of mass 10 kg moving along a straight line path with a velocity of 10 ms\(^{-1}\) in a time of 10 s is:

• A. \( 10 \, \text{N} \)
• B. \( 1000 \, \text{N} \)
• C. \( 100 \, \text{N} \)
• D. \( 1 \, \text{N} \)

Hint:

Remember that the force required to stop a body is related to its mass and the acceleration (or deceleration). In cases where the body comes to rest, use the formula \( F = ma \), where acceleration is the change in velocity over time.

Answer 1

The Correct Option is A

Step 1: Using Newton's Second Law of Motion.
The force \( F \) required to change the velocity of an object is: \[ F = ma \] where: \begin{itemize} \item \( m = 10 \, \text{kg} \), \item \( a = \frac{{v - u}}{{t}} = \frac{{0 - 10}}{{10}} = -1 \, \text{m/s}^2 \) (deceleration). \end{itemize}
Step 2: Calculate the force.
Using \( F = ma \), we get: \[ F = 10 \times (-1) = -10 \, \text{N} \] The magnitude of the force is \( 10 \, \text{N} \), which is the required force to stop the body.