An object has a position given by r = [2.0 m + (2.00 m/s)t] i + [3.0 m − (1.00 m/s^2)t^2] j, where quantities are in si units. what is the speed of the object at time t = 2.00 s?

1 m/s

Explanation:

We have an object whose position is given by a vector, where the components X and Y are identified by the unit vectors and (where each unit vector is defined to have a magnitude of exactly one):

On the other hand, velocity is defined as the variation of the position in time:

This means we have to derive :

This is the velocity vector

And when the velocity vector is:

This is the velocity vector at 2 seconds

However, the solution is not complete yet, we have to find the module of this velocity vector, which is the speed :

Finally:

This is the speed of the object at 2 seconds

weather forecasts are done by collecting data about the current state of the atmosphere mainly the temperature, humidity and wind and using meteorology, to determine the atmosphere that evolves over time. the h and l mean the high and low pressure. the red strip is a warm front. the blue strip is a cold front. the blue and red strip is a stationary front. the purple strip is a occluded front.

explanation: