Question

In figure CQ5.16, the light, taut, unstretchable cord B joins block 1 and the larger-mass block 2. Cord A exerts a fore on block 1 to make it accelerate forward.

(a) How does the magnitude of the force exerted by Cord A on block 1 compare with the magnitude of the force exerted by Cord B on block 2? Is it larger, smaller, or equal?

(b) How does the acceleration (if any) of block 2?

(c) Does cord B exert a force on block 1? If so, is it forward or backward? Is it larger, smaller, or equal in magnitude to the force exerted by cord B on block 2?

Short answer

1. The magnitude is larger.
2. The acceleration of block 2 is equal.
3. Yes, cord B exerts a force on block 1.

Step-by-step solution

Tension:

The stress on an object is equal to the product of the object's mass and the gravitational force added to the product of the mass and the acceleration.

(a) The magnitudes are compared:

The magnitude of the force exerted by Cord B on block 2 is larger, the tension in A must accelerate two blocks and not just one.

(b) Checking block 2's acceleration:

The acceleration of block two is equal. Whenever A moves by 1 cm, B moves by 1cm.

The two blocks have equal speeds at every instant and have equal acceleration.

(c) A force is exerted on block 1 by cord B:

Yes, cord B exerts a force on block 1 and exerts a force backward and is equal in magnitude to the force exerted by cord B on block 2.

The force of cord B on block 1 is the tension in the cord.