Answer:
The force do you need to exert to accomplish this is 56.98 N.
Explanation:
Given that,
Speed = 15.0 cm/s
Coefficient of kinetic friction = 0.444
Coefficient of static friction = 0.800
According to figure,
We need to calculate the angle of ramp
Using formula of angle
[tex]\theta=\tan^{-1}(\dfrac{2.5}{4.75})[/tex]
[tex]\theta=27.75^{\circ}[/tex]
Now as blocks are moving with no acceleration they can be considered as a system  and N be the normal force which applied by wedge on blocks  then perpendicular to slope of wedge,
(a). We need to calculate the force do you need to exert to accomplish this
Using balance equation
[tex]T+\mu N=mg\sin\theta[/tex]
Here,
[tex]N = mg\cos\theta[/tex]
[tex]\mu[/tex] = coefficient of kinetic friction
[tex]T=mg(\sin\theta-\mu\cos\theta)[/tex]
Put the value into the formula
[tex]T=80\times9.8(\sin27.75-0.444\cos27.75)[/tex]
[tex]T=56.98\ N[/tex]
Hence, The force do you need to exert to accomplish this is 56.98 N.
