Question

The motion of a particle along x axis is given by the equation x=9+5t 2 where x is the distance in m and t is time in second find the displacement after 3s and 5s average velocity ​

Answer 1

Answer:

Position at t=3 s, x1=9+5(3)2=54 cm

Position at t=5 s , x2=9+5(5)2=134 cm

The average velocity of an object is the ratio of change is position to time interval in which displacement occurs,i.e

v⃗ =displacementtime interval=∆x⃗ ∆t =x2−x1t2−t1=134 cm−54 cm5s−3s=802=40 cm/s

(2) Instantaneous velocity, vi=dxdt=d(9+5t2)dt=10t

at t=3s , vi=10(3)=30cm/s