Answer:
-18.283 N.
Explanation:
Using the equation of motion,
v² = u²+ 2as................ Equation 1
Where v = final velocity, u = initial velocity, a = acceleration, s = distance.
make a the subject of the equation
a = (v²-u²)/2s......... Equation 2
Given: u = 1.25 m/s, v = 0 m/s ( comes to rest), s = 2.20 m.
Substitute into equation 2
a = (0²-1.25²)/(2×2.2)
a = -1.5625/4.4
a = -0.355 m/s²
Note: The negative sign indicate that the swimmer is decelerating.
F = ma
Where F = force, m = mass of the swimmer.
Given: m = 51.5 kg.
F = 51.5(-0.355)
F = -18.283 N.
Note: The negative sign also mean that the force is in opposite direction to the motion of the swimmer