# math and physics

posted by steve Alexander

i just want to know form where i got on this formula the 4.9t² on this formula s=4.9t²+Vot+h because the book only say that a physics theory shows that when an object is thrown upward with an initial velocity Vo, its approximate height is given by that quadratic function

i will appreciate if you can explain me that because i have a math problem that uses that equation but i don't know from wheres that 4.9t²

1. bobpursley

It comes from calculus, and I assume you do not know that.

Newton found the velocity of a falling object was proportional to the time it fell.

vincreased= constant*time

but the constant we now call g, 9.8m/s^2, which comes from his universal gravitational equation.
From this, we get
Vfinal=vinitial+ g*time

Now the distance something falls is the average velocity, times time.
distance=(vfinal+vinitial)/2 * time
d=(1/2 (vinital+ g*time + vinitial)*time
= 1/2 (2vinitial*time + g*time^2)
= vinitial*time + 1/2 g*time^2
of course, 1/2 g = 4.9 m/s^2

## Similar Questions

1. ### Physics

A ball is thrown from ground level up in the air at 61m/s. How fast is the ball going 1s after being thrown. This problem wants you to use the formula v = (-1/2)gt^2 + v_0 g=9.8m/s^2 and v_0 = 61m/s so v = (-1/2)g*(1s)^2 + 61m/s at …
2. ### Physics

If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting position is about ?
3. ### calculus

an object is fired upward at the end of the burn it has an upward velocity of 245m/s and is 14.7 m high a) find the maximum height and when it is attained b) when it reaches the ground i know that i have to use the quadratic function …
4. ### algebra

Use the formula 4.9t^2 +vot=s, where t is the time in seconds, vo is the initial velocity, and s is the distance in meters. Approximately how far will an object fall in 4 seonds, if it is thrown downward at an initial velocity of 20 …
5. ### College Math

Another question which is confusing. The position of an object moving in a straight line is give by s=2t^2-3t, where is s in metres and t is the time in seconds the object has been in motion.. how long will it is take the object to …
6. ### URGENT MATH HELP!

When a ball is thrown upward, its height, h, in metres, is given by h=1.5 +19.6t -4.9t², where t is the number of seconds after it is thrown. For what length of time is the ball above the ground?
7. ### Math

The acceleration of an object g = -9.8 m/s^2. From the top of a building of 245 m., an object is thrown upwards at an initial velocity of 12m/s (a) What is the function for the velocity of the object?
8. ### algebra 1

The formula for the height of a falling object is shown below, where h is the height of the object in meters, t is the time in seconds, and k is the height, in meters, from which the object began its fall. h = –4.9t² + k If a rock …
9. ### Physics

Hi! i am going to apply for a medical study admission test and where just wondering if you guys could help me to come up with the formula for solving this problem. I am not looking for a answer, just the mathematical formula to solve …
10. ### Math

At a professional sports game, T-shirts are shot out of a small cannon into the crowd. Suppose a T-shirt is shot from 1 meter off the ground with an initial upward velocity of 20 meters per second. The height of the path of the shirt, …

More Similar Questions