If the product of the zeroes of the quadratic polynomial 3x² +5x-k^2 is -9, then the value of k is: (a) √3 (b) £2√3 (c) ±3√3 (d) 3
Answers
Answer:
Given,
Diameter of a wheel = 40
Let,
Number of Revolutions covered by wheel be 'n'
Distance covered by Wheel in 'n' Revolutions = 176m. i.e circumference covered by wheel in 'n' Revolutions.
To Find :-
Number of Revolutions.
Formula Required :-
Circumference of the Circle = 2πr.
Diameter of the Circle = 2 \sf\times× r
1m = 100cm
Solution :-
As the Wheel is in Circle Shape we can use the Formula of Circle.
Given, Diameter (d) = 40cm
Diameter = 2r
Radius(r) = \sf\dfrac{Diameter}{2}2Diameter
r = \sf\dfrac{40cm}{2}240cm
r = 20cm
\sf\therefore∴ Radius of the Circle = 20cm.
Circumference of the Circle in 'n' Revolutions = 176m
As 1m = 100cm
176m = 176 * 100cm = 17600cm
\sf\therefore∴ Circumference of the Circle in 'n' Revolutions = 17600cm.
Circumference on the Circle in 'n' Revolutions = n *2πr
π = \sf\dfrac{22}{7}722
Substituting Values :-
17600cm = n* 2 * \sf\dfrac{22}{7}722 * 20cm
17600cm = n*\sf\dfrac{880}{7}7880
n = \sf\dfrac{17600cm*7}{880}88017600cm∗7
n = \sf\dfrac{123200}{880}880123200
n = 140
\sf\therefore∴ Number of Revolutions Covered ny Wheel = 140