Question

Q. The position of an object moving along x-axis is given by x= a + bt2 where a=8.5m, b=2.5m/s2 and t is measured in seconds. What is its velocity at t=0s and t=2.0s. What is the average velocity b/w t=2.0s and t= 4.0s ?pls reply soon

Answer 1

x = a + bt^2
v = 2bt

Velocity at t = 0 is 0
Velocity at t = 2s is = 2*2.5*2 = 10 m/s

At t = 2s
x = 8.5 + 2.5*2^2
x = 18.5m

At t = 4s
x = 8.5 + 2.5*4^2
x = 48.5m

Average velocity = (48.5 - 18.5) / 2 = 18m/s

Answer 2

Answer:

The velocity at 0 seconds is 0, at 2 seconds is 18.5m/s, at 4 seconds is 48.5m/s, and the average velocity is 15m/s.

Explanation:

Given: x=a+bt²

a=8.5cm

b=2.5m/s²

Solution:
At t=0s

v=0m/s

At t=2s

x=8.5+2.5*4

∴x₁=18.5m/s

At t=4s

x=8.5+2.5*14

∴x₂=48.5m/s

Average velocity$=\frac{V2=V1}{2}$

=48.5-18.5/2

=15m/s

Therefore, the velocity at 0 seconds is 0, at 2 seconds is 18.5m/s, at 4 seconds is 48.5m/s, and the average velocity is 15m/s.