The negative sign on the acceleration is only a vector quantity that means the object is accelerating to the left. Hence, we can only focus on it magnitude which is 4 m/s^2. Acceleration is the change in velocity over time. The change in velocity must be 24 m/s - 0 m/s, if you want the object to stop. Therefore,
a = (v2 - v1)/t
4 = (24 - 0)t
t = 6 seconds
The object will stop after 6 seconds.
The deceleration experienced by the gymnast is the 9 times of the acceleration due to gravity.
Now from Newton`s first law, the net force on gymnast,

Here, W is the weight of the gymnast and a is the acceleration experienced by the gymnast (
acceleration due to gravity)
Therefore,
OR 
Given
and
Substituting these values in above formula and calculate the force exerted by the gymnast,


A 5kg backpack will weigh 49 newtons on earth
Answer:
A maximum
Explanation:
When displacement is maximum, velocity is Zero and vice versa
When displacement is maximum, acceleration is maximum and when it is zero, acc. Is zero
Answer: This type of questions are called probing questions. The correct option is D.
Explanation:
Probing questions are the type of questions that are asked to investigate an ongoing event. It helps the investigator to know more about what is happening and how to obtain conclusive decisions through the personal opinions of the respondent . For example from the question, Liza wanted to know more about the project updates which was held in the weekly meetings. She asked her employees questions like:
- Why were you late meeting your last deadline?
-Were there external factors that delayed your work?
-Did other coworkers get their part of the assignment to you on time?
- Do you need more help from me?".