Answer:
The statement is true: velocity and acceleration have opposite directions in the interval of braking.
Explanation:
Let's say we have a velocity
.
The acceleration
is the rate of change of the velocity
. This means that if
is <em>increasing during</em> time, then
must be positive. But if
is <em>decreasing over</em> time, then
will be negative (even though the velocity is positive).
Mathematically:

decreases ⇒
⇒
.
Example:

A cyclic, or not, group can have lots of sets of generators with different cardinalities, a cyclic group is characterized for having a generator set with 1 single element. A generator for a cyclic group and any other element will also be a generator set.
Answer:
Explanation:
Given that
Force constant k=8.6N/m
Weight =64g=64/1000=0.064kg
Extension is 45mm=45/1000= 0.045m
It will have it highest spend when the Potential energy is zero
Therefore energy in spring =change in kinetic energy
Ux=∆K.e
½ke² = ½mVf² — ½mVi²
Initial velocity is 0, Vi=0m/s
½ke² = ½mVf²
½ ×8.6 × 0.045² = ½ ×0.064 ×Vf²
0.0087075 = 0.032 Vf²
Then, Vf² = 0.0087075/0.032
Vf² = 0.2721
Vf=√0.2721
Vf= 0.522m/s
The time it will have this maximum velocity?
Using equation of motion
Vf= Vi + gr
0.522= 0+9.81t
t=0.522/9.81
t= 0.0532sec
t= 53.2 milliseconds
Hey there! :D
We want to find an answer choice that is reversible. If the physical change could have some way of being fixed, then it is a physical change. If it is a chemical change, the make-up is different and there is no way that it could change.
A cookie baking cannot be reversed. Cookies cannot go back to being cookie dough.
Paper burning cannot be reversed. Ashes and smoke cannot go back to being paper.
However, if your ice cream melts, you can refreeze it. Therefore, "3" is the best answer to the question.
I hope this helps!
~kaikers