Newton's First Law of Motion

A body of mass $m$ hangs at one end of a string of length $l$, the other end of which is fixed. It is given a horizontal velocity so that the string would just reach where it makes an angle of $60°$ with the vertical. The tension in the string at mean position is

Three forces acting on a body are shown in the figure. To have a resultant force only along the $Y-\mathrm{axis}$, the magnitude of the minimum additional force needed is:

The rough surface of a horizontal table offers a definite maximum opposing force to initiate the motion of a block along the table, which is proportional to the resultant normal force given by the table. Forces $\mathrm{F}1$ and $\mathrm{F}2$ act at the same angle $\mathrm{\theta }$ with the horizontal and both are just initiating the sliding motion of the block along the table. Force $\mathrm{F}1$ is a pulling force while the force $\mathrm{F}2$ is a pushing force. $\mathrm{F}2 > \mathrm{F} 1$ , because

Consider following forces: $\left(\mathrm{w}\right)$ Force due to tension along a string,$\left(\mathrm{x}\right)$ Normal force given by a surface, $\left(\mathrm{y}\right)$ Force due to air resistance and $\left(\mathrm{z}\right)$Buoyant force or upthrust given by a fluid. Which of these are electromagnetic forces?

Assertion : Both the string $AB$ and $CD$ have equal tensile strength. If the lower string is pulled gradually then the upper string is more likely to break, but if the lower string is pulled with a jerk, then the lower string is more likely to break.

Reason : Due to the property of inertia the position of the block doesn't change suddenly. However its position can charge gradually.

Two persons are holding a rope of negligible weight tightly at its ends so that it is horizontal. $\mathrm{A} 15 \mathrm{kg}$ weight is attached to the rope at the mid point which now no longer remains horizontal. The minimum tension required to completely straighten the rope is :

Look at the following road stud lights. These are eco friendly lights.

How do these lights get energy?

In which of the following games do you have to pull in order to win the game?

Which of the following breaks down in our body to release energy.

If Work is represented by ‘W’ then which of the following formula can be applied to calculate work?

Give reason:

Mahesh rolled a marble on the floor. After some time the marble stopped moving.

Rehan is shifting the furnitures of his room to his sister’s room. In which of the following case has he done more work?

State whether true or false.

‘Energy can be stored and can be used to apply force’.