00:01
In this problem, we have been given that there is a particle which is moving along x -axis, and its equation is given as x equals 10 t minus 2 t square.
00:11
So here time is in seconds and x is in meters.
00:15
And we are required to determine the instantaneous velocity when t is equal to two seconds and the instantaneous velocity when t is equal to three seconds.
00:28
So first let's do this.
00:29
Here we use this equation according to which the instantaneous velocity, that is the rate of change of position.
00:36
So we just differentiate this x with respect to t and we get v as 10 when we differentiate 10 t minus 4 t when we differentiate minus 2 t square.
00:47
And now we have the expression for instantaneous velocity as a function of time.
00:52
Let's substitute t as two seconds.
00:55
So when t is two seconds, we is 10 minus four times...