Help me please For a velocity versus time graph how do you know what the velocity is at a certain
time? How do you know the acceleration at a certain time? How do you know the
Displacement at a certain time?

For a velocity versus time graph how do you know what the velocity is at a certain  time?

Ans: By drawing a line parallel to the y axis (Velocity axis) and perpendicular to the co-ordinate of the Time on the x axis (Time Axis). The point on the slope of the graph where this line intersects, will be the desired velocity at the certain time.

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How do you know the acceleration at a certain time?

Hence,

By dividing the difference of the Final and Initial Velocity by the Time Taken, we could find the acceleration.

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How do you know the  Displacement at a certain time?

Ans: As Displacement equals to the area enclosed by the slope of the Velocity-Time Graph, By finding the area under the slope till the perpendicular at the desired time, we find the Displacement.

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the moon affects the earth gravitation ally, causing certain motions of that body and also producing tides in its ocean and atmosphere. the tidal wave in our atmosphere is, however, far too minute to be an effective cause in any known meteorological phenomenon.

explanation:

490 n

f=125n a=2.5m/s2