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You pull a box with a constant force across a frictionless table using an attached to
tionless table using an attached rope held horizontally. If
you then pull the box with the same force but now at an angle to the horizontal (the box
now at an angle to the horizontal (the box remains flat on the
table), does the acceleration of the box:
A. remain the same
B. increase
C. decrease
D. there is no acceleration
E. the angle needs to be known

I know that answer is C but can someone explain why thank you​

Respuesta :

MathPhys

Explanation:

From Newton's second law, the net force equals the mass times acceleration.

∑F = ma

The acceleration of the box is caused by the horizontal component of the force.  Applying Newton's law in the x direction:

F cos θ = ma

When the rope is horizontal, θ = 0, so cos θ = 1.

As θ increases, cos θ decreases.  So the acceleration decreases.

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