how do you know in a problem ; what formula to use and what the displacement , final velocity , initial velocity , time , acceleration , is ?
To determine which formula and variables to use in a problem, you need to understand the concept being described and use your knowledge of the relevant physics equations. Here are the definitions of the variables you mentioned:
- Displacement (d or Δx) refers to the change in position of an object in a given direction.
- Final velocity (vᵢ) represents the instantaneous velocity of an object at the end of a given time frame.
- Initial velocity (v₀) denotes the velocity of an object at the beginning of a given time frame.
- Time (t) refers to the duration or the interval during which an object is observed.
- Acceleration (a) is the rate at which an object's velocity changes over time.
Here are a few common formulas that relate these variables:
1. Displacement formula: d = vᵢt + 0.5at²
This formula relates displacement (d), initial velocity (vᵢ), time (t), and acceleration (a).
2. Final velocity formula: vᵢ = v₀ + at
This formula relates final velocity (vᵢ), initial velocity (v₀), acceleration (a), and time (t).
3. Displacement formula for constant velocity: d = vᵢt
This formula relates displacement (d), initial velocity (vᵢ), and time (t) when acceleration is zero.
These are just a few examples, and there are many other equations that apply to different scenarios, such as uniformly accelerated motion or free-fall. Understanding the concept being described in the problem and recognizing the relevant variables will help determine which formula to use. Additionally, it is always a good practice to cross-check the units of the variables to ensure they align with the units expected in the equation.