Question

the position of an object moving along x-axis is given by x=a+bt^2 where a = 8.5m and b=2.5m s and t is measured in second. If the object starts from t= 0 , you he velocity at t=2 s​

Answer 1

Answer:

V= dx/ dt

V = d(a+bt^2)/ dt

differentiation of a is zero.

differentiation of bt^2 is 2bt^2-1/ 2-1

= 2bt

so, V= 2bt

V = 2× 2.5 × 2

V = 10m/s

Answer 2

Explanation:

Position is given as x=a+bt

2

=8.5+2.5t

2

Position at t=2 s, x

2

=8.5+2.5(2)

2

=18.5 m

Position at t=4 s, x

1

=8.5+2.5(4)

2

=48.5 m

Displacement S=x

2 −x 1 =48.5−18.5=30 m

Time taken t=4−2=2 s

Average velocity Vavg

= S/t = 2/30

=15 m/s