In the following figure, the force F is gradually increased from zero. Draw the graph between the magnitude of F and the tension T in the string. The coefficient of static friction between the block and the ground is μ. Assume coefficient of kinetic friction and that of static friction to be equal.
In the following figure, the force F is gradually increased from zero. Draw the graph between the magnitude of F and the tension T in the string. The coefficient of static friction between the block and the ground is μ. Assume coefficient of kinetic friction and that of static friction to be equal.
The correct option is B
As the external force F is gradually increased from zero, it is compensated by the friction and the string bears no tension. Mathematically,
F-fr=0 (where the force of friction fr<μmg)
When limiting friction is achieved by increasing force F to a value till μmg, then
F-μmg > 0. So, tension will come to action
F-μmg-T=0. So, when F<μmg, the friction is static and it is equal to F, and when F>μmg, the tension in the string becomes F−μmg. As you can see, that tension will now increase linearly with F and the slope will be 1. Hence, option (b) is correct.
As the external force F is gradually increased from zero, it is compensated by the friction and the string bears no tension. Mathematically,
F-fr=0 (where the force of friction fr<μmg)
When limiting friction is achieved by increasing force F to a value till μmg, then
F-μmg > 0. So, tension will come to action
F-μmg-T=0. So, when F<μmg, the friction is static and it is equal to F, and when F>μmg, the tension in the string becomes F−μmg. As you can see, that tension will now increase linearly with F and the slope will be 1. Hence, option (b) is correct.
