The ratio of the distance moved by the point at which the effort is applied in a simple machine to the distance moved by the point at which the load is applied, in the same time. In the case of an ideal (frictionless and weightless) machine, velocity ratio = mechanical advantage. Velocity ratio is sometimes called distance ratio.
Answer:
4.28 s
Explanation:
after two seconds (2 s) His friends is
d = 3.5 m/s x 2 s = 7 meter ahead.
in this state, a bicylist start from initial velocity vo = 0 m/s and accelerat 2.4 m/s²
then, when bicylist reach his friend
t friend = t bicyclist = t
d bicylist = d friend + d
-------
d friend = 3.5 . t
d bicylist = vo . t + ½ a t²
d friend + d = vo . t + ½ a t²
3.5 t + 7 = 0 . t + ½ . 2.4 . t²
3.5 t + 7 = 1.2 t²
0 = 1.2 t² - 3.5 t - 7
t = -1.363 and t = 4.28
take the positive one
If an atom<span>, ion, or molecule is at the </span>lowest possible energy<span> level, it and </span>its electrons<span> are said to be in the ground </span>state<span>. If it is at a higher </span>energy<span> level, it is said to be excited, or any </span>electrons<span> that </span>have<span> higher </span>energy<span> than the ground </span>state<span> are excited.</span>
They all have to do something with physics?
Let 
and 
be the vectors, and let 
be their common magnitude.
The resultant 
is 
times larger in magnitude than either vector alone, so 
.
Recall the dot product identity
where 
is the angle between the vectors 
and 
. In the special case of 
, we get
Now, to get the angle between and , we have
To compute the dot product, we take the dot product of the resultant with itself.
Solve for 
.
Since their dot product is zero, and are perpendicular, so 
.
