Explanation:
Given that,
The initial velocity of a skater is, u = 5 m/s
She slows to a velocity of 2 m/s over a distance of 20 m.
We can find the acceleration of skater. It is equal to the rate of change of velocity. So, it can be calculated using third equation of motion as follows :

a = acceleration

So, her acceleration is
and she is deaccelerating. Also, her initial velocity is given i.e. 5 m/s.
Answer:
33 N
Explanation:
v = Velocity of fluid = 8+2 = 10 m/s
= Density of fluid = 1.2 kg/m³
C = Coefficient of drag = 1.1
A = Cross sectional area = 0.5 m²
Drag force is given by

The drag force on the athlete is 33 N
Answer: to provide evidence to a theory
Explanation: Experimentation allows for multiple trials to provide evidence to a scientific theory. Without experimentation there would be no data to back up your hypothesis.
<span>The cation is positively charged and has a charge twice that of the anion, for example +2.
The anion is negatively charged and in our example where the cation has a +2 charge, it must have a -1 charge.
In order for the charges to equal zero, there must be two anions: -1 x 2 = -2
So the answer is D. AX2</span>