Acceleration due to gravity question.

In summary, gravity accelerates objects at a constant rate of 9.8 meters per second, per second. This means that the speed of an object increases by 9.8 meters per second every second. The equation for distance fallen due to gravity is s = 1/2*g*t^2, where g is the acceleration due to gravity (9.8 m/s/s) and t is the time in seconds. This equation can be used to calculate the distance an object falls under the influence of gravity.
  • #1
inertiaforce
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1
I am not a physics professional. I just have found a casual interest in physics. I have a question about gravity.

Gravity accelerates objects at 9.8 meters per second, per second. I will round this off to 10 meters per second per second.

Does this mean that for every second, the rate of acceleration increases? In other words, after the 2nd second, the rate of acceleration is 20 meters per second? After the third second, the rate of acceleration is 30 meters per second? Is the RATE of acceleration increasing by 10 meters per second for every second so that after 20 seconds the rate of acceleration would be 200 meters per second?
 
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  • #2
inertiaforce said:
I am not a physics professional. I just have found a casual interest in physics. I have a question about gravity.

Gravity accelerates objects at 9.8 meters per second, per second. I will round this off to 10 meters per second per second.

Does this mean that for every second, the rate of acceleration increases? In other words, after the 2nd second, the rate of acceleration is 20 meters per second? After the third second, the rate of acceleration is 30 meters per second? Is the RATE of acceleration increasing by 10 meters per second for every second so that after 20 seconds the rate of acceleration would be 200 meters per second?
No, it's the speed that is increasing, not the acceleration. Speed is in meters per second and that speed increases as an object falls. The acceleration is the rate of change of that speed, in meters per second per second. That acceleration is a constant.
 
  • #3
Doc Al said:
No, it's the speed that is increasing, not the acceleration. Speed is in meters per second and that speed increases as an object falls. The acceleration is the rate of change of that speed, in meters per second per second. That acceleration is a constant.

Ok. So the acceleration remains at 10 meters per second then?

If that's true, why is it said that the rate of acceleration due to gravity is 10 meters per second PER SECOND? Why is that 2nd "per second" there? Why don't they just say the rate of acceleration is 10 meters per second? Why 10 meter per second PER SECOND?
 
  • #4
inertiaforce said:
Ok. So the acceleration remains at 10 meters per second then?

If that's true, why is it said that the rate of acceleration due to gravity is 10 meters per second PER SECOND? Why is that 2nd "per second" there? Why don't they just say the rate of acceleration is 10 meters per second? Why 10 meter per second PER SECOND?
Meters per second is the units for speed, not acceleration.

The acceleration is 10 m/s per second. That means every second the speed increases by 10 m/s.
 
  • #5
Thanks for clearing that up. I had some confusion about whether it was just the speed that was increasing, or both the speed and the rate of the acceleration.

Seems like you've cleared that up for me.

Is there a math equation that describes the rate of acceleration due to gravity? My father told me he had seen an equation with t squared in it. Are you familiar with any such equation?
 
  • #6
inertiaforce said:
Thanks for clearing that up. I had some confusion about whether it was just the speed that was increasing, or both the speed and the rate of the acceleration.

Seems like you've cleared that up for me.
Good!

Is there a math equation that describes the rate of acceleration due to gravity? My father told me he had seen an equation with t squared in it. Are you familiar with any such equation?
Here are some equations that describe falling motion under gravity.

a = g = 9.8 m/s/s. (This just says that the acceleration is a constant 'g', which is 9.8 m/s/s.)

v = a*t = g*t (This gives the speed of a falling body at any time after it's dropped. So, after 1.5 seconds, v = 9.8*1.5 = 14.7 m/s.)

s = 1/2*a*t^2 = 1/2*g*t^2 (This is the equation you were looking for. It gives the distance fallen, s, as a function of time. So, after 1.5 seconds, the object falls a distance of s = .5*9.8*1.5^2 = 11 m.)
 
  • #7
That sounds like the equation for the distance an object falls under the influence of gravity. If you drop an object from rest, after t seconds it has fallen the distance
$$s = \frac{1}{2}gt^2$$
(Added: Doc Al beat me to it while I was typing...)
 
  • #8
jtbell said:
(Added: Doc Al beat me to it while I was typing...)

haha
 

1. What is acceleration due to gravity?

Acceleration due to gravity refers to the rate at which an object falls towards the Earth's surface due to the force of gravity. It is a constant value, denoted as "g", and is approximately 9.8 meters per second squared (m/s^2). This means that for every second an object falls, its velocity increases by 9.8 m/s.

2. How is acceleration due to gravity calculated?

The acceleration due to gravity can be calculated using the formula g = G * M / R^2, where G is the universal gravitational constant, M is the mass of the object, and R is the distance between the object and the center of the Earth. However, for most practical purposes, g is simply considered to be a constant value of 9.8 m/s^2.

3. Does acceleration due to gravity change on different planets?

Yes, the acceleration due to gravity can vary on different planets depending on their mass and size. For example, on the Moon where the mass and size are smaller than Earth, the acceleration due to gravity is only 1.6 m/s^2. Similarly, on larger planets like Jupiter, the acceleration due to gravity is much greater than on Earth.

4. Does the acceleration due to gravity affect all objects equally?

Yes, the acceleration due to gravity affects all objects equally regardless of their mass. This is known as the principle of equivalence, which states that the gravitational force acting on an object is proportional to its mass.

5. How does air resistance affect the acceleration due to gravity?

Air resistance, also known as drag, can affect the acceleration due to gravity by slowing down the rate at which an object falls. This is because the force of air resistance acts in the opposite direction of the gravitational force, causing the object to experience a net force that is less than the force of gravity. As a result, the object's acceleration is reduced.

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