CBSE Class 10 Maths (Standard) 2024 · Paper 30/2/1 · Question 36

Polynomials 4 marks Medium

A ball is thrown in the air so that

t

seconds after it is thrown, its height

h

metre above its starting point is given by the polynomial

h = 25 t - 5 t^{2}

. Observe the graph of the polynomial and answer the following questions.

Graph of h = 25t − 5t² with zeroes at 0 and 5

(i)Write zeroes of the given polynomial.[1]
(ii)Find the maximum height achieved by ball.[1]
(iii)(a)After throwing upward, how much time did the ball take to reach a height of $30$ m ?[2]
(iii)(b)(OR) Find the two different values of $t$ when the height of the ball was $20$ m.[2]

Answer

(i) The zeroes are

t = 0

and

t = 5

; (ii) The maximum height is

31.25

m, reached at

t = 2.5

s; (iii)(a) The ball takes

2

s to reach

30

m (it passes

30

m again at

t = 3

s on the way down); (iii)(b) The height is

20

m at

t = 1

s and at

t = 4

🔒 Step-by-step solution