Answer:
8m/s
Explanation:
Average Speed = distance / time = 400/50 = 8m/s
Respiratory and circulatory
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:
