TinyProf
TinyProf
Join Waitlist

Calculate the angular acceleration of a system at t = 4 seconds using a provided angular velocity graph | Step-by-Step Solution

PhysicsKinematics
Explained on January 12, 2026
📚 Grade 9-12🟡 Medium⏱️ 15-20 min
Problem

Problem

Angular velocity of a system: Part A | Problem The figure below shows the angular velocity for a system graphed as a function where all horizontal divisions are in seconds and all vertical divisions are in rad/s. At t = 4 s, the system is at an angular position of -1 rad. What is the angular acceleration (in rad/s²) of the system at t = 4 s?

🎯 What You'll Learn

  • Analyze angular velocity graphs
  • Calculate angular acceleration from a graph
  • Understand relationships between position, velocity, and acceleration

Prerequisites: Basic graphing skills, Understanding of velocity and acceleration, Interpreting graphical representations

💡 Quick Summary

Hi there! I can see you're working with angular kinematics, specifically finding angular acceleration from a graph - this is a great way to visualize rotational motion concepts. The key insight here is thinking about the relationship between angular velocity and angular acceleration - what does angular acceleration represent in terms of how angular velocity changes over time? Take a look at your angular velocity vs. time graph and consider what you'd need to examine at the specific moment when t = 4 seconds. Remember that in kinematics, acceleration is always related to how velocity changes, so think about what mathematical operation you'd use to find the rate of change from a graph. You've got the right setup here, and once you identify what to look for on that graph at t = 4s, the solution will follow naturally!

Step-by-Step Explanation

Hello! Great question about angular kinematics!

What We're Solving:

We need to find the angular acceleration of a system at t = 4 seconds using a graph that shows angular velocity (ω) versus time.

The Approach:

Angular acceleration is the rate of change of angular velocity. Just like how linear acceleration is the slope of a velocity-time graph, angular acceleration is the slope of an angular velocity-time graph!

The mathematical relationship is: α = dω/dt (angular acceleration = change in angular velocity / change in time)

So we need to find the slope of the ω vs. t graph at t = 4 seconds.

Step-by-Step Solution:

Step 1: Understand what we're looking for

  • Angular acceleration (α) has units of rad/s²
  • We need the instantaneous angular acceleration at exactly t = 4 s
Step 2: Locate t = 4 s on the graph
  • Find the point on the curve where t = 4 seconds
  • Note the angular velocity value at this point
Step 3: Determine the slope at t = 4 s
  • If the graph shows a straight line at t = 4 s, calculate: slope = Δω/Δt
  • Choose two nearby points and find: (ω₂ - ω₁)/(t₂ - t₁)
  • If it's a curve, you'll need the instantaneous slope (tangent line at that point)
Step 4: Apply the correct sign
  • Positive slope = positive angular acceleration
  • Negative slope = negative angular acceleration
  • Zero slope = zero angular acceleration

The Answer:

Without seeing your specific graph, I can't give you the numerical answer, but once you find the slope of the ω vs. t graph at t = 4 seconds, that value (in rad/s²) will be your angular acceleration!

For example, if the slope at t = 4 s is +2 rad/s per second, then α = +2 rad/s².

Memory Tip:

Remember the relationship chain: Position → Velocity → Acceleration
  • Angular position (θ) → Angular velocity (ω) → Angular acceleration (α)
  • Each step to the right involves taking a derivative (finding the slope)!
  • ω = dθ/dt and α = dω/dt
The angular position given (-1 rad at t = 4 s) is extra information for other parts of this problem, but not needed for finding angular acceleration.

⚠️ Common Mistakes to Avoid

  • Misreading the graph scales
  • Confusing velocity with acceleration
  • Not carefully examining the graph's slope changes

This explanation was generated by AI. While we work hard to be accurate, mistakes can happen! Always double-check important answers with your teacher or textbook.

Prof

Meet TinyProf

Your child's personal AI tutor that explains why, not just what. Snap a photo of any homework problem and get clear, step-by-step explanations that build real understanding.

  • Instant explanations — Just snap a photo of the problem
  • Guided learning — Socratic method helps kids discover answers
  • All subjects — Math, Science, English, History and more
  • Voice chat — Kids can talk through problems out loud

Trusted by parents who want their kids to actually learn, not just get answers.

Prof

TinyProf

📷 Problem detected:

Solve: 2x + 5 = 13

Step 1:

Subtract 5 from both sides...

Join our homework help community

Join thousands of students and parents helping each other with homework. Ask questions, share tips, and celebrate wins together.

Students & ParentsGet Help 24/7Free to Join
Join Discord Community

Need help with YOUR homework?

TinyProf explains problems step-by-step so you actually understand. Join our waitlist for early access!

👤
👤
👤
Join 500+ parents on the waitlist