- #1

rudransh verma

Gold Member

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- Homework Statement
- Three blocks of mass 10, 6,4 kgs are placed on friction less surface. Force of 40N pulls the system. Calculate T.

- Relevant Equations
- ##F=ma##

$$a= -40/(10+6+4)$$

$$a=-2 m/s^2$$

Taking one mass of 10 kg.

$$T-40=10(-2)$$

$$T=20 N$$

This is correct.

But if I make the eqn of the system then

$$-40+T-T+T-T=20(-2)$$

I have also drawn the diagram. It looks like the second body m2 is subject to no force. But it’s accelerating. How?

$$a=-2 m/s^2$$

Taking one mass of 10 kg.

$$T-40=10(-2)$$

$$T=20 N$$

This is correct.

But if I make the eqn of the system then

$$-40+T-T+T-T=20(-2)$$

I have also drawn the diagram. It looks like the second body m2 is subject to no force. But it’s accelerating. How?