Question

The displacement of a particle along the X-axis is given as
x=5t2+1
, where x is in metres and t in seconds. Calculate its instantaneous velocity 2 s.
46 m/s
40 m/s
20 m/s
25 m/s

Answer 1

Question

The displacement of a particle along the X-axis is given as $x = 5t^2 + 1$, where $x$ is in metres and $t$ in seconds. Calculate its instantaneous velocity 2 s.

a) $46\ \mathrm{m/s}$

b) $40\ \mathrm{m/s}$

c) $20\ \mathrm{m/s}$

d) $25\ \mathrm{m/s}$

Solution

$$v(t) = \frac{dx}{dt} = 2 * 5 * t = 10t$$ $$v(2) = 10 * 2 = 20\ \mathrm{m/s}$$

Answer: c) $v(2) = 20\ \mathrm{m/s}$