Rate of Change of Quantities

IMPORTANT

Rate of Change of Quantities: Overview

This topic covers concepts, such as Application of Derivative, Rate of Change of Quantities, Instantaneous Rate of Change of a Function w.r.t. another Function, Marginal Cost, Instantaneous Rate of Change of a Function, etc.

Important Questions on Rate of Change of Quantities

HARD
IMPORTANT

The length x of a rectangle is decreasing at the rate of   5cm/minute  and the width y is increasing at the rate of   4cm/minute  When   x=8cmandy=6cm,  the rate of change of (a) the perimeter, b the area of the rectangle would be:

MEDIUM
IMPORTANT

A ladder 5m long is leaning against a wall. The bottom of the ladder is pulled along the ground, away from the wall, at the rate of   2cm s -2 . How fast is its height on the wall decreasing when the foot of the ladder is 4m away from the wall?

EASY
IMPORTANT

A particle moves along a straight line according to the law s=13t3-3t2+9t+17, where 's' is in meter and 't' is in second. Its velocity decreases in

HARD
IMPORTANT

Water is running into an underground right circular conical reservoir, which is 10 m deep and radius of its base is 5 m. If the rate of change in the volume of water in the reservoir is 32πm3min, then the rate (in mmin) at which water rises in it, when the water level is 4 m, is

MEDIUM
IMPORTANT

If the volume of a sphere is increasing at a constant rate, then the rate at which its radius is increasing,is

MEDIUM
IMPORTANT

In which of the following range x lies such that 9x2-12x-40 increases more rapidly than 2x3+7.

EASY
IMPORTANT

At which point on the parabola x2=4y, the rate of increase of the x- coordinate is the same as the rate of the increase of y- coordinate

MEDIUM
IMPORTANT

If there is 2% error in measuring the radius of Sphere, then .......... will be the percentage error in the surface area.

EASY
IMPORTANT

If y=7x-x3 and x increases at the rate of 4 units per second, then the rate of change in slope of the curve when x=3, is

MEDIUM
IMPORTANT

A point on the parabola y2=18x at which the ordinate increases at twice the rate of the abscissa is:

EASY
IMPORTANT

At which point on the parabola x2=4y, the rate of increase of the x- coordinate is the same as the rate of the increase of y- coordinate.

EASY
IMPORTANT

A point on the parabola y2=18x at which the ordinate increases at twice the rate of the abscissa, is

EASY
IMPORTANT

The distance in meters covered by a body in t seconds, is given by s=3t2-8t+5.

The body will stop after

HARD
IMPORTANT

There are two points moving along the y-axis which are given by y=20+6t, y=13+t2. Find velocity at which they are approaching  each other at the time of encounter (in cm/sec)

MEDIUM
IMPORTANT

If the rate of change of area of rhombus with respect to it's side is equal to the side of rhombus, then the angles of rhombus are

MEDIUM
IMPORTANT

The displacement is 's' of the particle at time 't' is given by s=t3-4t2-52. Find its velocity and acceleration at time t=2s.

HARD
IMPORTANT

The surface area of a spherical balloon is increasing at the rate of 2 cm2/sec. If the volume of the balloon is increasing at a cm3/sec, when the radius of the balloon is 6 cm, then a is

MEDIUM
IMPORTANT

The approximate value of cos31° is (take 1°=0.0174 )

EASY
IMPORTANT

The x-coordinate changes on the curve y=3x5+15x-8 at the rate of 15units/secAx1, y1, Bx2, y2 are the points on the curve at which the y-coordinate changes at the rate of 6 units/sec, then the slope of AB=

EASY
IMPORTANT

The population of a city grows at the annual rate of 3%. What percentage increase is expected in 5 years?