Question: The co-ordinates of a moving particle at time 𝑡 are given by 𝑥 = 𝑐𝑡 2 and 𝑦 = 𝑏𝑡 2 . The instantaneous speed of the particle is
(A) 2𝑡(𝑏 + 𝑐)
(B) 2+\left( b+c\right) ^{1/2}
(C) 2t\left( c^{2}-b^{2}\right)
(D) 2t\left( c^{2}+b^{2}\right) ^{1/2}
Answer: option (D)
Solution:
