English

A ball is thrown in the air. Its height at any time t is given by h = 3 + 14t – 5t2 . Find the maximum height it can reach. - Mathematics and Statistics

Advertisements
Advertisements

Question

A ball is thrown in the air. Its height at any time t is given by h = 3 + 14t – 5t2. Find the maximum height it can reach.

Sum

Solution

The height h at any t is given by h = 3 + 14t – 5t2 

∴ `"dh"/dt = d/dt(3 + 14t - 5t^2)`

= 0 + 14 x 1 – 5 x 2t

= 14 – 10t

and `(d^2h)/(dt^2) = d/dt(14 - 10t)`

= 0 – 10 x 1

= – 10

The root of `"dh"/dt` = 0,

i.e. 14 – 10t = 0 is t = `(14)/(10) = (7)/(5)`
and
`((d^2h)/(dt^2))_("at" t = 7/5)` = −10 < 0

∴ By the second derivative test, h is maximum at t = `(7)/(5)`.

∴ Maximum height = `(3 + 14t  – 5t^2)_("at" t = 7/5)`

= `3 + 14(7/5) - 5(7/5)^2`

= `3 + (98)/(5) - (245)/(25)`

= `(75 + 490 - 245)/(25)`

= `(320)/(25)`

= 12.8

Hence, the maximum height the ball can reach = 12.8 units.

shaalaa.com
  Is there an error in this question or solution?
Chapter 2: Applications of Derivatives - Exercise 2.4 [Page 90]

APPEARS IN

Video TutorialsVIEW ALL [2]

RELATED QUESTIONS

An open box is to be made out of a piece of a square card board of sides 18 cms by cutting off equal squares from the comers and turning up the sides. Find the maximum volume of the box.


Find the maximum and minimum value, if any, of the following function given by f(x) = 9x2 + 12x + 2


Find the maximum and minimum value, if any, of the following function given by g(x) = − |x + 1| + 3.


Find the maximum and minimum value, if any, of the following function given by h(x) = sin(2x) + 5.


Find the local maxima and local minima, if any, of the following function. Find also the local maximum and the local minimum values, as the case may be:

f(x) = x3 − 6x2 + 9x + 15


Find the local maxima and local minima, if any, of the following function. Find also the local maximum and the local minimum values, as the case may be:

`g(x) = x/2 + 2/x, x > 0`


Prove that the following function do not have maxima or minima:

f(x) = ex


Prove that the following function do not have maxima or minima:

h(x) = x3 + x2 + x + 1


Find the absolute maximum value and the absolute minimum value of the following function in the given interval:

`f(x) = 4x - 1/x x^2, x in [-2 ,9/2]`


Find the maximum profit that a company can make, if the profit function is given by p(x) = 41 − 72x − 18x2.


What is the maximum value of the function sin x + cos x?


Find two positive numbers x and y such that their sum is 35 and the product x2y5 is a maximum.


A rectangular sheet of tin 45 cm by 24 cm is to be made into a box without top, by cutting off square from each corner and folding up the flaps. What should be the side of the square to be cut off so that the volume of the box is the maximum possible?


Show that the right circular cylinder of given surface and maximum volume is such that is heights is equal to the diameter of the base.


A wire of length 28 m is to be cut into two pieces. One of the pieces is to be made into a square and the other into a circle. What should be the length of the two pieces so that the combined area of the square and the circle is minimum?


Show that the semi-vertical angle of the cone of the maximum volume and of given slant height is `tan^(-1) sqrt(2)`


Show that semi-vertical angle of right circular cone of given surface area and maximum volume is  `Sin^(-1) (1/3).`


Find the maximum area of an isosceles triangle inscribed in the ellipse  `x^2/ a^2 + y^2/b^2 = 1` with its vertex at one end of the major axis.


Show that the surface area of a closed cuboid with square base and given volume is minimum, when it is a cube.


A metal box with a square base and vertical sides is to contain 1024 cm3. The material for the top and bottom costs Rs 5 per cm2 and the material for the sides costs Rs 2.50 per cm2. Find the least cost of the box


An open tank with a square base and vertical sides is to be constructed from a metal sheet so as to hold a given quantity of water. Show that the cost of material will be least when the depth of the tank is half of its width. If the cost is to be borne by nearby settled lower-income families, for whom water will be provided, what kind of value is hidden in this question?


Show that the cone of the greatest volume which can be inscribed in a given sphere has an altitude equal to \[ \frac{2}{3} \] of the diameter of the sphere.


Prove that the semi-vertical angle of the right circular cone of given volume and least curved surface is \[\cot^{- 1} \left( \sqrt{2} \right)\] .


Find the maximum and minimum of the following functions : y = 5x3 + 2x2 – 3x.


Find the maximum and minimum of the following functions : f(x) = `x^2 + (16)/x^2`


Find the maximum and minimum of the following functions : f(x) = `logx/x`


A wire of length 36 metres is bent in the form of a rectangle. Find its dimensions if the area of the rectangle is maximum.


The perimeter of a triangle is 10 cm. If one of the side is 4 cm. What are the other two sides of the triangle for its maximum area?


The profit function P(x) of a firm, selling x items per day is given by P(x) = (150 – x)x – 1625 . Find the number of items the firm should manufacture to get maximum profit. Find the maximum profit.


Solve the following : Show that of all rectangles inscribed in a given circle, the square has the maximum area.


Solve the following :  A window is in the form of a rectangle surmounted by a semicircle. If the perimeter be 30 m, find the dimensions so that the greatest possible amount of light may be admitted.


Solve the following : Show that the height of a right circular cylinder of greatest volume that can be inscribed in a right circular cone is one-third of that of the cone.


Solve the following:

A wire of length l is cut into two parts. One part is bent into a circle and the other into a square. Show that the sum of the areas of the circle and the square is the least, if the radius of the circle is half of the side of the square.


Solve the following : Show that the altitude of the right circular cone of maximum volume that can be inscribed in a sphere of radius r is  `(4r)/(3)`.


Solve the following : Show that the height of the cylinder of maximum volume that can be inscribed in a sphere of radius R is `(2"R")/sqrt(3)`. Also, find the maximum volume.


Determine the maximum and minimum value of the following function.

f(x) = 2x3 – 21x2 + 36x – 20


Determine the maximum and minimum value of the following function.

f(x) = `x^2 + 16/x`


Divide the number 20 into two parts such that their product is maximum.


A wire of length 120 cm is bent in the form of a rectangle. Find its dimensions if the area of the rectangle is maximum


If f(x) = px5 + qx4 + 5x3 - 10 has local maximum and minimum at x = 1 and x = 3 respectively then (p, q) = ______.


The minimum value of Z = 5x + 8y subject to x + y ≥ 5, 0 ≤ x ≤ 4, y ≥ 2, x ≥ 0, y ≥ 0 is ____________.


If R is the circum radius of Δ ABC, then A(Δ ABC) = ______.


The maximum value of function x3 - 15x2 + 72x + 19 in the interval [1, 10] is ______.


The minimum value of the function f(x) = 13 - 14x + 9x2 is ______


The two parts of 120 for which the sum of double of first and square of second part is minimum, are ______.


An open box with square base is to be made of a given quantity of cardboard of area c2. Show that the maximum volume of the box is `"c"^3/(6sqrt(3))` cubic units


Find the points of local maxima and local minima respectively for the function f(x) = sin 2x - x, where `-pi/2 le "x" le pi/2`


Find the volume of the largest cylinder that can be inscribed in a sphere of radius r cm.


The coordinates of the point on the parabola y2 = 8x which is at minimum distance from the circle x2 + (y + 6)2 = 1 are ____________.


The distance of that point on y = x4 + 3x2 + 2x which is nearest to the line y = 2x - 1 is ____________.


The function `"f"("x") = "x" + 4/"x"` has ____________.


A ball is thrown upward at a speed of 28 meter per second. What is the speed of ball one second before reaching maximum height? (Given that g= 10 meter per second2)


Read the following passage and answer the questions given below.


The temperature of a person during an intestinal illness is given by f(x) = 0.1x2 + mx + 98.6, 0 ≤ x ≤ 12, m being a constant, where f(x) is the temperature in °F at x days.

  1. Is the function differentiable in the interval (0, 12)? Justify your answer.
  2. If 6 is the critical point of the function, then find the value of the constant m.
  3. Find the intervals in which the function is strictly increasing/strictly decreasing.
    OR
    Find the points of local maximum/local minimum, if any, in the interval (0, 12) as well as the points of absolute maximum/absolute minimum in the interval [0, 12]. Also, find the corresponding local maximum/local minimum and the absolute ‘maximum/absolute minimum values of the function.

A wire of length 22 m is to be cut into two pieces. One of the pieces is to be made into a square and the other into an equilateral triangle. Then, the length of the side of the equilateral triangle, so that the combined area of the square and the equilateral triangle is minimum, is ______.


The range of a ∈ R for which the function f(x) = `(4a - 3)(x + log_e5) + 2(a - 7)cot(x/2)sin^2(x/2), x ≠ 2nπ, n∈N` has critical points, is ______.


If p(x) be a polynomial of degree three that has a local maximum value 8 at x = 1 and a local minimum value 4 at x = 2; then p(0) is equal to ______.


Let f(x) = (x – a)ng(x) , where g(n)(a) ≠ 0; n = 0, 1, 2, 3.... then ______.


The set of values of p for which the points of extremum of the function f(x) = x3 – 3px2 + 3(p2 – 1)x + 1 lie in the interval (–2, 4), is ______.


Let f(x) = |(x – 1)(x2 – 2x – 3)| + x – 3, x ∈ R. If m and M are respectively the number of points of local minimum and local maximum of f in the interval (0, 4), then m + M is equal to ______.


A rectangle with one side lying along the x-axis is to be inscribed in the closed region of the xy plane bounded by the lines y = 0, y = 3x and y = 30 – 2x. The largest area of such a rectangle is ______.


The maximum value of z = 6x + 8y subject to constraints 2x + y ≤ 30, x + 2y ≤ 24 and x ≥ 0, y ≥ 0 is ______.


The volume of the greatest cylinder which can be inscribed in a cone of height 30 cm and semi-vertical angle 30° is ______.


The minimum value of the function f(x) = xlogx is ______.


A straight line is drawn through the point P(3, 4) meeting the positive direction of coordinate axes at the points A and B. If O is the origin, then minimum area of ΔOAB is equal to ______.


Check whether the function f : R `rightarrow` R defined by f(x) = x3 + x, has any critical point/s or not ? If yes, then find the point/s.


A right circular cylinder is to be made so that the sum of the radius and height is 6 metres. Find the maximum volume of the cylinder.


Find the point on the curve y2 = 4x, which is nearest to the point (2, 1).


A box with a square base is to have an open top. The surface area of box is 147 sq. cm. What should be its dimensions in order that the volume is largest?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×