The frictional force is 15 N
Explanation:
In order to solve this problem, we can apply Newton's second law of motion, which states that the net force acting on an object is equal to the product between its mass and its acceleration:
[tex]\sum F = ma[/tex]
where
[tex]\sum F[/tex] is the net force
m is the mass
a is the acceleration
Here we are just interested in the situation along the horizontal direction. The net force acting on the block is:
[tex]\sum F = F_a -F_f[/tex]
where
[tex]F_a = 40 N[/tex] is the applied force (forward)
[tex]F_f[/tex] is the frictional force (backward)
m = 5 kg is the mass of the block
[tex]a=5 m/s^2[/tex] is the acceleration
Substituting into the equation and solving, we find the frictional force:
[tex]F_a-F_f = ma\\F_f = F_a-ma=40-(5)(5)=15 N[/tex]
Learn more about Newton's second law:
brainly.com/question/3820012
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