Answer:
The object will have an upward acceleration
Explanation:
Let's consider the forces applied on the box. We have only two forces:
- The applied force of push, [tex]F_p[/tex], downward
- The force of gravity, [tex]W[/tex], (also known as weight of the object), downward
Therefore, the net force on the box is:
[tex]F_{net}=F_p -W[/tex]
Here, we know that force applied is equal or greater than the weight, so
[tex]F_p \geq W[/tex]
And therefore the net force is greater than zero:
[tex]F_{net}\geq 0[/tex] (1)
According to Newton's second law of motion, the net force on the box is equal to the product between its mass and its acceleration:
[tex]F_{net}=ma[/tex]
where
m is the mass of the box
a is its acceleration
Given (1), this means that
[tex]a\geq 0[/tex]
Therefore, the box will have an upward acceleration.
In this case force example we have:
[tex]F_p = 100 N\\W = 40 N[/tex]
So the mass of the box is
[tex]m=\frac{W}{g}=\frac{40}{10}=4 kg[/tex]
So the net force is
[tex]F_{net}=F_p-W=100-40=60 N[/tex]
And the acceleration is
[tex]a=\frac{F_{net}}{m}=\frac{60}{4}=15 m/s^2[/tex]
