Question: Two forces are applied to a 45 kg box, as shown. The box is on a smooth surface.Which statement best describes the acceleration of the box? Assuming the diagram is similar to the one attached.
A) The box accelerates at 1.0 m/s² to the right because the net force is 45 N to the right.
B) The box accelerates at 1.9 m/s² to the right because the greater force is to the right.
C) The box accelerates at 3.0 m/s² because the combined forces cause the box to accelerate.
D) The box does not accelerate, because neither force is large enough to move the box.
Answer:
A) The box accelerates at 1.0 m/s² to the right because the net force is 45 N to the right.
Explanation:
From the diagram attached,
F₂-F₁ = ma.................. Equation 1
Where F₂ = Force acting to the rigth, F₁ = Force acting to the left, m = mass of the box, a = acceleration of the box.
Make a the subject of the equation
a = (F₂-F₁)/m............... Equation 2
also from the diagram
Given: F₂ = 55 N, F₁ = 10 N, m = 45 kg.
Substitute these values into equation 2
a = (55-10)/45
a = 45/45
a = 1 m/s²
Hence the box accelerate at 1.0 m/s² to the right because the net force is 45 N to the right. Hence the right option is A.
