How can you accurately find the initial velocity of a toy gun?

Click For Summary

Discussion Overview

The discussion focuses on methods to accurately determine the initial velocity of a toy gun, specifically considering the effects of air resistance and various measurement techniques. The scope includes experimental approaches and conceptual understanding of velocity measurement.

Discussion Character

  • Exploratory
  • Technical explanation
  • Experimental/applied

Main Points Raised

  • Some participants suggest using a ballistic pendulum to measure the initial velocity by observing how high the pendulum rises after being struck by the projectile.
  • Others question the decision to disregard air resistance, implying that it may be important for accurately determining the initial velocity.
  • One participant proposes using slow-motion filming with a digital camera as an alternative method, noting that some cameras can capture at high frame rates, which could aid in measurement.
  • There is a suggestion that the exit velocity of the projectile is relevant to the measurement method being considered.

Areas of Agreement / Disagreement

Participants express differing views on the importance of air resistance in the measurement process, indicating a lack of consensus on whether it should be disregarded. Multiple methods for measuring initial velocity are proposed, but no single method is universally agreed upon as the best.

Contextual Notes

Some assumptions about the measurement techniques and their accuracy are not fully explored, and the discussion does not resolve the implications of air resistance on the initial velocity measurement.

RobSGo
Messages
1
Reaction score
0
Disregarding air resistance, how could you find an accurate number for the initial velocity of a toy gun?
 
Physics news on Phys.org
Ballistic pendulum? Fire it into a pendulum so that it sticks and see how high the pendulum goes?

Welcome to Physics Forums!
 
RobSGo said:
Disregarding air resistance, how could you find an accurate number for the initial velocity of a toy gun?

Welcome to the PF.

Why would you disregard air resistance? Do you want to know Vo or not?
 
berkeman said:
Welcome to the PF.

Why would you disregard air resistance? Do you want to know Vo or not?

The exit velocity is the velocity, whatever you are firing into. I think, by "disregarding air resistance" he refers to the measurement method. If he is, then observing the maximum height achieved (KE=GPE) would be a way forward (or up haha). The ballistic pendulum would be more accurate and repeatable, once he's got his technique right.
 
sophiecentaur said:
The ballistic pendulum would be more accurate and repeatable, once he's got his technique right.
The pendulum is probably the best way.

But you can also check if your digital camera supports slow motion filming. Some cameras below 500$ can film at more than 1000fps, which should be enough for a "toy gun". The pixel resolution is usually low, but sufficient if you place the camera right next to the muzzle.
 

Similar threads

High School Can energy be decomposed?
  • · Replies 2 ·
Replies
2
Views
2K
High School Path traced by a point on the periphery of the ball? Helix?
  • · Replies 6 ·
Replies
6
Views
1K
How can you identify the type of gun by the sound it makes?
  • · Replies 9 ·
Replies
9
Views
4K
High School In uniform acceleration, mean velocity ##\bar v = \frac{v_0+v}{2}##?
  • · Replies 23 ·
Replies
23
Views
3K
Projectile motion, initial height and range given, find initial velocity
  • · Replies 8 ·
Replies
8
Views
2K
High School Is the final velocity of a Tossed tomato the same as its initial velocity
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad How come you have to use work energy to find v0 of spring?
  • · Replies 9 ·
Replies
9
Views
2K
High School The Effect of Linear and Rotational Motion on Measured Weight
  • · Replies 10 ·
Replies
10
Views
1K
High School How is tangential velocity measured in m/s when it’s r * w?
  • · Replies 41 ·
2
Replies
41
Views
3K
High School Understanding Momentum: The Relationship Between Mass, Velocity, and Force
  • · Replies 29 ·
Replies
29
Views
3K