Use the formula below for this question:

re-arrange to solve for a:

now simply plug in your variables and there's your answer :). If you ever get stuck, you can look up the kinematic equations!
Answer:
no not always sometimes they react at all so false I hope I helped :)
Options A and D are correct. The strength of the force of friction depends on the objects' sizes and weights and the heat generated by the friction and the types of surfaces involved.
<h3 /><h3>What is the friction force?</h3>
It is a type of opposition force acting on the surface of the body that tries to oppose the motion of the body. its unit is Newton (N).
Mathematically, it is defined as the product of the coefficient of friction and normal reaction.
On resolving the given force and acceleration in the different components and balancing the equation gets. Components in the x-direction.
The strength of the force of friction depends on the two factors, as;
A. The objects' sizes and weights.
D. The heat generated by the friction and the types of surfaces involved.
Hence, options A and D are correct.
To learn more about the friction force, refer to the link;
brainly.com/question/1714663
#SPJ1
A=f/m
A=900/425
A=2.18
To determine acceleration you divide the force by the mass.
Average speed is the ratio of total distance moved by Chi in total time interval
So here we will have
Total distance = 100 m + 400 m

Total time taken = 5 min + 15 min = 20 min

now by the formula of average speed we know that



so average speed will be 1.5 km/h