If the distance covered by an object in time t is given by s(t) = 2t2 + 3t, where s(t) is in meters and t is in seconds, what is the average velocity over the interval from 2 seconds to 4 seconds?
15 meters/second
14 meters/second
13 meters/second
12 meters/second
11 meters/second

Question

If the distance covered by an object in time t is given by s(t) = 2t2 + 3t, where s(t) is in meters and t is in seconds, what is the average velocity over the interval from 2 seconds to 4 seconds?
15 meters/second
14 meters/second
13 meters/second
12 meters/second
11 meters/second

pratyush5 · Answer

Do you know differential calculus ?

anonymous · Answer

no im new to this??

anonymous · Answer

s=2t^2+3t
Differentiate the above equation with respect to t..we get,
ds/dt=4t+3
We know that ds/dt=velocity
Therefore, v=4t+3
Put different values for t and get the answer..all the best :)

pratyush5 · Answer

@sid0830 has done exactly what I said. So basically you don't know diffrentiation ? right ?

anonymous · Answer

i got a difference of 8?

pratyush5 · Answer

@davidza6496 I need you to confirm me one thing. Did you get how @sid0830 arrived at 4t + 3 ? If not there is another easy way of doing this.

anonymous · Answer

yeah i understand it now!! thanks

pratyush5 · Answer

So now plug in the values of t = 2 and t = 4. So what values of 'v' do you get ?

anonymous · Answer

i got 11 for 2 and 19 for 4

anonymous · Answer

@pratyush5

pratyush5 · Answer

Brilliant now we know average velocity = v1 + v2 whole divide by 2. So we get 11+19/2 = 10/2 = 15