In a hydrogen atom, the distance between the electron and proton is $2.5 \times {10^{ - 11}}\,m$. The electrical force of attraction between them will be

Adjoining figure shows a force of $40\, N$ acting at $30^o$ to the horizontal on a body of mass $5 \,kg$ resting on a smooth horizontal surface. Assuming that the acceleration of free-fall is $10\, ms^{-2}$, which of the following statements is (are) correct?

$[1]$ The horizontal force acting on the body is $20\, N$

$[2]$ The weight of the $5\, kg$ mass acts vertically downwards

$[3]$ The net vertical force acting on the body is $30\, N$

A uniform rope of mass $M$ and length $L$ is fixed at its upper end vertically from a rigid support. Then the tension in the rope at the distance $l$ from the rigid support is $x$

Block $A$ of mass $4 \;kg$ is to be kept at rest against a smooth vertical wall by applying a force $F$ as shown in figure. The force required is .......... $N$ $\left(g=10 m / s ^2\right)$

A rope of length $L$ is pulled by a constant force $F$. What is the tension in the rope at a distance $x$ from the end where the force is applied

Write Aristotle’s law regarding motion.