What is the change of speed over time?

Click For Summary
SUMMARY

The discussion centers on the concept of speed and its change over time, specifically identifying that the rate of change of speed is known as acceleration. Key formulas for kinematics are provided, including s = ut + 1/2 at², v = u + at, and v² = u² - 2as, which are essential for understanding motion under constant acceleration. An additional formula, s = 1/2(u + v)t, is also mentioned as useful for deriving other kinematic equations. These formulas are sufficient for basic kinematic analysis.

PREREQUISITES
  • Understanding of basic physics concepts such as displacement, velocity, and acceleration.
  • Familiarity with kinematic equations and their applications.
  • Knowledge of algebra for rearranging formulas.
  • Basic grasp of motion under constant acceleration.
NEXT STEPS
  • Study the derivation of kinematic equations in physics textbooks.
  • Learn about the implications of constant versus variable acceleration.
  • Explore real-world applications of kinematics in engineering and physics.
  • Investigate advanced topics such as projectile motion and circular motion.
USEFUL FOR

Students of physics, educators teaching kinematics, and anyone interested in understanding motion and acceleration in physical systems.

pavadrin
Messages
154
Reaction score
0
2day i started a new topic inj physics and there were a few terms which i am unsure of. if velocity is the change of displacement over time, and acceleration is the change of velocity, and if speed is the change of distance over time, what is the change of speed over time? also i have come across a few formulas for this topic, these formulas are listed below
s = ut + \frac{1}{2} at^2

v = u + at

v^2 = u^2 - 2as

v_{average} = \frac{s}{t}

a_{average} = \frac{v - u}{t}

are these all the formulas that are required for this topic or are there more? i understand that in some cases they may need to be rearanged.
many thanks,
Pavadrin
 
Physics news on Phys.org
The rate of change of speed with respect to time is often termed acceleration, although I do not care for its use. The the formulae you list are valid for constant acceleration in kinematics (except the average acceleration as that obviously can be used universally). The formulae are all that are required for basic kinematics however, there is a further formulae, s = \frac{1}{2}(u+v)t, that may be useful but it is derived from the above formulae.
 
thanks Hootenanny for the relpy and additional formula :smile:
Pavadrin
 
pavadrin said:
thanks Hootenanny for the relpy and additional formula :smile:
Pavadrin
My pleasure :smile:
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
7
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 84 ·
3
Replies
84
Views
5K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
1
Views
2K
  • · Replies 12 ·
Replies
12
Views
1K
  • · Replies 5 ·
Replies
5
Views
977
  • · Replies 8 ·
Replies
8
Views
1K