A box is moved 10 m across a smooth floor by a force F making a downward angle with the floor, so that there is effectively a 4 N force acting parallel to the floor in the direction of motion and a 3 N force acting perpendicular to the floor. The force F acts for 20 seconds. The impulse delivered to the box by the floor during this process has magnitude
A- 80 Ns
B- 60 Ns
C- 100 Ns
D- zero
E- can't tell without know the mass of the box

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aristocles aristocles · Answer 1 · 2019-10-28T04:30:49+01:00

Answer:

E- can't tell without know the mass of the box

Explanation:

Impulse due to a force is given as

[tex]impulse = F\times \Delta t[/tex]

now we will have

net force in vertical direction is ZERO as there is no acceleration in this direction

so we will have

[tex]F_y + mg = F_n[/tex]

Here we know that

[tex]F_y = 3 N[/tex]

now we have

[tex]F_n = mg + 3[/tex]

now without known the mass of the box we cant find the normal force on the box

so it is not possible to find the impulse on the box