Answer:
F = 102 N
Explanation:
ASSUMING the track is horizontal to avoid gravity potential energy considerations.
The work of the applied force must overcome friction work and increase the kinetic energy of the runner
F(d) = Ff(d) + ½m(v² - u²)
F = Ff + m(v² - u²) / 2d
F = 30.0 + 60.0(8.00² - 2.00²) / (2(25.0))
F = 102 N
The density differences in the ocean water are due to different salt concentration and differences in temperature. B) temperature
Use the equation

plug in the variables for the equation. Use 0 for Vf because at the highest point the velocity would be zero. Use -9.8 for acceleration because that is the speed at which gravity pulls down.

your answer would be 2.06122 seconds.
Answer:
1411.8 N/m
Explanation:
From Hooke's law;
F= Ke
Where
F= force on the spring
K= force constant
e = extension
But e= 8.50 × 10^-2m
F= weight = 12.0 kg × 10 = 120 N
K = F/e = 120/8.50 × 10^-2
K= 1411.8 N/m