Question

The x and y coordinates of a particle at any time t are given by x = 2t + 4t² and y = 5t, where x and y are in metre and t in second. The acceleration of the particle at t = 5 s is –

• A. 40 m s^–2
• B. 20 m s^–2
• C. 8 m s^–2
• D. Zero

Answer 1

Answer: (C)

8 m s^–2

Answer 2

v_x = $\frac { \mathrm { dx } } { \mathrm { dt } }$ = 2 + 8t and a_x = $\frac { \mathrm { dv } _ { \mathrm { x } } } { \mathrm { dt } }$ = 8

v_y = $\frac { \mathrm { dy } } { \mathrm { dt } }$ = 5 and a_y = $\frac { d v _ { \mathrm { y } } } { \mathrm { dt } }$ = 0