0-60 time of Gravity

[Stu]

OK, so what's the time taken to accelerate to 62mph of something dropping in freefall (ignoring wind resistance)
I reckon it's about 5 secs, but can't prove it.

[Stingo]

See here....

Acceleration is the rate of change of velocity of an object.

where a is acceleration, v is the final velocity of the object, u is the initial velocity of the object and t is the time that has elapsed.
This equation can be rearranged to give:

• v = u + at

If s represents the displacement of the object, then:

• s = ½ (u + v)t
• s = ut + ½ at2
• v2 = u2 + 2as

These equations are true if the acceleration of the body in question is constant (i.e. it doesn’t change over the time period). The units used must be consistent, and the standard units are:
Acceleration: ms-2(or m/s2)
Velocity: ms-1 (or m/s)
Displacement: m
Time: s
The equation which you will need to use depends upon the question.
The Acceleration due to Gravity

If a body is dropped from a height, it will accelerate because of gravity. The acceleration caused by gravity is written as “g”, and is usually taken to be 9.8 ms-2.
Example

A ball is dropped from the leaning tower of Pisa, at a height of 50m from the ground. The ball is dropped from rest and falls freely under gravity. How long will it be before the ball hits the ground?
We know: s = 50, a = 9.8, u = 0 and we want to find t.
The equation connecting these four is s = ut + ½ at2
So 50 = 0 + ½ × 9.8 × t2
Rearranging: t2 = 10.20408
t = 3.19…
the time taken is 3.19s (3sf)

Originally Posted by Stu

OK, so what's the time taken to accelerate to 62mph of something dropping in freefall (ignoring wind resistance)
I reckon it's about 5 secs, but can't prove it.

gravitational acceleration is approx 9.81 m/s^2

hth

Should be about 2.82 seconds ignoring all other factors.

Gravitational acceleration constant is IIRC 9.81m/s/s and 62mph is about 27.71m/s

so acceleration to 62mph = 27.71/9.81 = 2.82 approx.

Is that right?

That depends on how high up you start from, and the mass of the object that you're dropping.

Acceleration due to gravity:
where G is Newton's gravitational constant, is the mass of the earth and r is the distance to the center of the earth. In as much as the radius of the earth is very large compared to laboratory dimensions, an object near the surface of the earth, r is approximately constant and equal to the radius of the earth,

It's possible to experience constant acceleration, if you're "near" the surface of the earth, or the relative mass is "insignificant."

3.19 secs eh?
All I've got to do is find a cliff and I can personally give a GSXR1
a run for its money.



No comments about doing people a favour please.

0-60 : 4 secs silver 03 cbr600


All im interested in mate

[Stu]

Gosh Stingo, you typed that all out by hand in 4 minutes good effort, shame it didn't answer the question!

Sarah HTH - No I already had that.

I had the 28meters per second & 10 meters per second squared, didn't realise you could just divide one by the other. Thanks

Was reading about Northwind's Veypor giving him a G force of .74 & Jelster ridiculing him for it not being more than 1G.

Originally Posted by Stu

Gosh Stingo, you typed that all out by hand in 4 minutes good effort, shame it didn't answer the question!

Sarah HTH - No I already had that.

I had the 28meters per second & 10 meters per second squared, didn't realise you could just divide one by the other. Thanks

Was reading about Northwind's Veypor giving him a G force of .74 & Jelster ridiculing him for it not being more than 1G.

i was too lazy to convert mph to m/s

So does the plane take off or not?