$A$ rider on horseback falls when the horse starts running all of a sudden because:

Give two points of difference between mass and weight.

$A$ body of mass $2 \, kg$ is sliding with a constant velocity of $4 \, m/s$ on a frictionless horizontal table. The force required to keep the body moving with the same velocity is .......... $N$.

An astronaut accidentally gets separated from his small spaceship accelerating in interstellar space at a constant rate of $100 \; m/s^2$. What is the acceleration of the astronaut the instant after he is outside the spaceship (in $; m/s^2$)? (Assume that there are no nearby stars to exert gravitational force on him.)

$Assertion$ : The driver in a vehicle moving with a constant speed on a straight road is an inertial frame of reference.
$Reason$ : $A$ reference frame in which Newton's laws of motion are applicable is non-inertial.

Three forces given by vectors $2 \hat{i} + 2 \hat{j}$,$2 \hat{i} - 2 \hat{j}$,and $-4 \hat{i}$ are acting together on a point object at rest. The object moves along the direction: