The tension in the rope securing the upper pulley and the force that must be applied to keep the system in equilibrium ​

Explanation:

In a frictionless system with no acceleration, the tension in the rope must be F along its entire length

FBD analysis of the lower pulley has two upward acting tension vectors F and one downward acting weight vector W

2F = W

F = W/2

FBD analysis of the upper pulley has one upward acting support vector T and three downward acting tension vectors F

T = 3F

T = 3(W/2)

T = 1.5W

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer