The motion of a stone thrown vertically upward is given by $s = 13.8t - 4.9t^2$,where $s$ is in meters and $t$ is in seconds. Then its velocity at $t = 1$ second is ........ $m/s$.

$A$ particle moving from a fixed point on a straight line travels a distance $S$ metres in $t$ seconds. If $S = t^3 - t^2 - t + 3$,then the distance (in metres) travelled by the particle when it comes to rest is:

The equation of motion of a particle is $s = at^2 + bt + c$. If the displacement after $1 \text{ s}$ is $20 \text{ m}$,velocity after $2 \text{ s}$ is $30 \text{ m/s}$,and the acceleration is $10 \text{ m/s}^2$,then:

Coffee is draining from a conical filter,with both height and diameter equal to $15 \, cm$,into a cylindrical coffee pot with a diameter of $15 \, cm$. The rate at which coffee drains from the filter into the pot is $100 \, cm^3/min$. The rate in $cm/min$ at which the level in the pot is rising at the instant when the coffee in the pot is $10 \, cm$ deep,is:

If the radius of a circle increases at the rate of $7 \text{ cm/sec}$,then the rate of increase of its area after $10 \text{ minutes}$ is:

If the surface area of a sphere of radius $r$ is increasing uniformly at the rate $8 \, cm^2/s$,then the rate of change of its volume is