Answer:
Please, read the anser below
Explanation:
1. In order to calculate the acceleration of the children you use the Newton second law for the summation of the implied forces:
(1)
Where is has been used that the motion is in the direction of the applied force by the second child
F2: force of the second child = 92N
F1: force of the first child = 79N
Ff: friction force = 5.5N
M: mass of the third child = 24kg
a: acceleration of the third child = ?
You solve the equation (1) for a, and you replace the values of the other parameters:
The acceleration is 0.48m/s^2
2. The system of interest is the same as before, the acceleration calculated is about the motion of the third child.
3. An image with the diagram forces is attached below.
4. If the friction would be 150N, the acceleration would be zero, because the friction force is higher than the higher force between children, which is 92N.
Then, the acceleration is zero
