Answer:
a = Δv/t = (vf - vi)/t = (0 - 5)/4 = -1.25 m/s²
Explanation:
You may or may not need the negative sign, depending on how the question designer was thinking about the problem.
The velocity of B after elastic collision is 3.45m/s
This type of collision is an elastic collision and we can use a formula to solve this problem.
<h3>Elastic Collision</h3>

The data given are;
- m1 = 281kg
- u1 = 2.82m/s
- m2 = 209kg
- u2 = -1.72m/s
- v1 = ?
Let's substitute the values into the equation.

From the calculation above, the final velocity of the car B after elastic collision is 3.45m/s.
Learn more about elastic collision here;
brainly.com/question/7694106
Compound; consists of atoms of two or more different elements bound together,can be broken down into a simpler type of matter (elements) by chemical means (but not by physical means) has properties that are different from its component elements, and always contains the same ratio of its component atoms.Mixtures; Note that a mixture:consists of two or more different elements and/or compounds physically intermingled, can be separated into its components by physical means, and often retains many of the properties of its components.
A spring scale measures weight because <span>It works by Hooke's Law, which states that the force needed to extend a </span>spring<span> is proportional to the distance that </span>spring<span> is extended from its rest position. Therefore, the </span>scale<span> markings on the </span>spring<span> balance are equally spaced. A </span>spring scale<span> can</span>not measure mass<span>, only </span>weight<span>. hope that helped</span>
Explanation:
Formula to calculate angular acceleration is as follows.

or, 
Putting the given values into the above formula as follows.

=
= 0.326 
Thus, we can conclude that the wheel’s angular acceleration if its initial angular speed is 2.5 rad/s is 0.326
.