Newton's Second Law — Prelims Questions

A constant force acts on an object of mass $5\,\text{kg}$ for a duration of $2\,\text{s}$, increasing its velocity from $4\,\text{m/s}$ to $8\,\text{m/s}$. The magnitude of the force applied is:

A block of mass $2\,\text{kg}$ is placed on a frictionless horizontal surface. Two forces, $F_1 = 10\,\text{N}$ acting horizontally to the right and $F_2 = 4\,\text{N}$ acting horizontally to the left, are applied to the block. What is the acceleration of the block?

A $10\,\text{kg}$ block is pulled by a rope with a tension of $30\,\text{N}$ at an angle of $30^\circ$ above the horizontal. If the surface is frictionless, what is the horizontal acceleration of the block? (Given $\cos 30^\circ = 0.866$)

A $5\,\text{kg}$ block is pulled up a frictionless inclined plane that makes an angle of $30^\circ$ with the horizontal by a force of $50\,\text{N}$ parallel to the incline. What is the acceleration of the block? (Take $g = 10\,\text{m/s}^2$)

Two blocks of masses $m_1 = 2\,\text{kg}$ and $m_2 = 3\,\text{kg}$ are connected by a massless string and placed on a frictionless horizontal surface. A horizontal force $F = 20\,\text{N}$ is applied to $m_1$. What is the tension in the string connecting the two blocks?

A person of mass $60\,\text{kg}$ is standing on a weighing machine inside an elevator. If the elevator is accelerating upwards at $2\,\text{m/s}^2$, what is the reading on the weighing machine? (Take $g = 10\,\text{m/s}^2$)