AP Physics B&C – Free Response Practice Question on Newton’s Laws

The following question will be useful for AP Physics B as well as AP Physics C aspiramts. Parts (a), (b), (c) and (d) of the question are meant for B as well as C. Part (d) of the question is meant additionally for AP physics C aspirants. Here is the question:

In the adjoining figure P1 and P2 are light frictionless pulleys. P1 is fixed and P2 is movable. The strings used are inextensible and of negligible mass. The fixed pulley P₁ carries a mass M₁ and the movable pulley P₂ carries a mass M₂ which has one and a half times the mass of M₁. Now, answer the following questions:

(a) How is the tension T₁ in the string attached to the mass M₁ related to the tension T₂ in the string attached to the mass M₂?

Justify your answer.

(b) How is the magnitude of acceleration a₁ of the mass M₁ related to the magnitude of acceleration a₂ of the mass M₂?

Justify your answer

(c) From the following options regarding the motion of the mass M₁, select the correct one by putting a tick (√) mark:

Mass M₁ will be accelerated upwards ______

Mass M₁ will be accelerated downwards ______

Mass M₁ will move with uniform velocity ______

Justify your answer.

(d) Determine the accelerations a₁ and a₂ of the masses M₁ and M₂ respectively.

(e) Determine the tensions T₁ and T₂ in the strings attached to the masses M₁ and M₂ respectively.

Try to answer the above question. I’ll be back soon with a model answer for your benefit.

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