Is Gravitational Acceleration Positive or Negative in Upward Motion Problems?

In summary, gravitational acceleration is the measure of how quickly an object's velocity changes as it falls towards the center of a planet or other massive body. It is calculated using the formula a = GM/r^2, and the average value on Earth is 9.8 m/s^2, although it can vary slightly. Gravitational acceleration causes objects to accelerate towards the center of a massive body, leading to falling or orbiting depending on the object's velocity. The value of gravitational acceleration differs on other planets, such as 3.7 m/s^2 on Mars and 24.8 m/s^2 on Jupiter.
  • #1
jamiebean
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Homework Statement
A boy throws a stone vertically up with a speed 24.6 m/s. Assuming that the stone's motion is affected by the gravitaional acceleration only (acceleration g=9.8ms-2). What is the displacement in m between the stone's position at time 3.8 s and its initial position? (hint: displacement has a sign "+" or "-", the canvas system can accept signed input. upward direction is "+" and the downward direction is "-", gravitation acceleration is negative in sign)
Relevant Equations
d=vi x t + (at^2)/2
gravitation acceleration= -9.8
I attempted the question with
d=vi x t + (at^2)/2
gravitation acceleration= -9.8
and I got the solution of 22.724.

Should I use the value of -9.8? or should I just use 9.8?

should I use the equation above? I feel like what I am calculating is not displacement but distance...
thank you
 
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  • #2
The question says that upwards is positive. That means that the gravitational acceleration is ...
 
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Likes jamiebean
  • #3
PeroK said:
The question says that upwards is positive. That means that the gravitational acceleration is ...
thanks a lot! I have got this problem right!love yah
 

What is gravitational acceleration?

Gravitational acceleration is a measure of how quickly objects accelerate towards each other due to the force of gravity. It is typically denoted as "g" and has a value of approximately 9.8 meters per second squared on Earth's surface.

How is gravitational acceleration calculated?

Gravitational acceleration can be calculated using the formula g = G * M / r^2, where G is the universal gravitational constant, M is the mass of the larger object, and r is the distance between the two objects. On Earth, this formula simplifies to g = 9.8 m/s^2.

How does gravitational acceleration differ on other planets?

Gravitational acceleration varies depending on the mass and size of the planet. For example, on the moon, gravitational acceleration is only 1.62 m/s^2, while on Jupiter it is 24.79 m/s^2. This means that objects will accelerate towards the surface at a slower or faster rate depending on the planet.

What are some real-life examples of gravitational acceleration?

Gravitational acceleration is responsible for objects falling to the ground when dropped, as well as the motion of celestial bodies in the solar system. It also plays a role in the tides on Earth, with the moon's gravitational pull causing the tides to rise and fall.

How does gravitational acceleration affect humans?

Humans have evolved to adapt to the gravitational acceleration on Earth, and it is an important factor in our daily lives. Our bodies are designed to function in a certain gravitational environment, so changes in this acceleration can have an impact on our health and physical abilities.

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