Skip to main content
Ch 04: Kinematics in Two Dimensions
Chapter 4, Problem 4

FIGURE EX4.24 shows the angular-position-versus-time graph for a particle moving in a circle. What is the particle's angular velocity at (b) t = 4sAngular position vs. time graph for a particle in circular motion, showing angular velocity at t=4s.

Verified step by step guidance
1
Identify the time interval in which t = 4s falls. From the graph, it is within the interval from 0s to 5s.
Determine the angular position (θ) at the beginning and end of this interval. At t = 0s, θ = 0 rad, and at t = 5s, θ = 2π rad.
Calculate the change in angular position (Δθ) over this interval: Δθ = θ_final - θ_initial = 2π rad - 0 rad.
Determine the time interval (Δt) over which this change occurs: Δt = 5s - 0s = 5s.
Calculate the angular velocity (ω) using the formula ω = Δθ / Δt. Substitute the values: ω = (2π rad) / (5s).

Verified Solution

Video duration:
2m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Angular Position

Angular position refers to the angle at which an object is located in a circular path, measured in radians. In the context of the graph, it shows how the angle changes over time as the particle moves in a circle. The vertical axis represents angular position, indicating the particle's orientation at any given moment.
Recommended video:
Guided course
14:03
Rotational Position & Displacement

Angular Velocity

Angular velocity is the rate of change of angular position with respect to time, typically expressed in radians per second. It can be calculated by determining the slope of the angular position versus time graph. At t = 4s, the angular velocity can be found by analyzing the graph's slope during that interval, which indicates how quickly the particle is rotating.
Recommended video:
Guided course
06:18
Intro to Angular Momentum

Graph Interpretation

Interpreting graphs is crucial in physics for understanding relationships between variables. In this case, the angular position versus time graph allows us to visualize how the particle's position changes over time. By examining the graph's segments, we can identify periods of constant angular velocity and periods of acceleration or deceleration, which are essential for solving the problem.
Recommended video:
Guided course
07:32
Graphing Position, Velocity, and Acceleration Graphs
Related Practice
Textbook Question
The radius of the earth's very nearly circular orbit around the sun is 1.5 x 10^11m. Find the magnitude of the earth's (b) angular velocity
626
views
Textbook Question
Communications satellites are placed in a circular orbit where they stay directly over a fixed point on the equator as the earth rotates. These are called geosynchronous orbits. The radius of the earth is 6.37 x 10⁶ m, and the altitude of a geosynchronous orbit is 3.58 x 10⁷ m (≈ 22,000 miles). What are (a) the speed and (b) the magnitude of the acceleration of a satellite in a geosynchronous orbit?
1424
views
Textbook Question
FIGURE EX4.23 shows the angular-velocity-versus-time graph for a particle moving in a circle. How many revolutions does the object make during the first 4 s?

1719
views
2
rank
Textbook Question
The earth's radius is about 4000 miles. Kampala, the capital of Uganda, and Singapore are both nearly on the equator. The distance between them is 5000 miles. The flight from Kampala to Singapore takes 9.0 hours. What is the plane's angular velocity with respect to the earth's surface? Give your answer in degrees/h.
1234
views
Textbook Question
As the earth rotates, what is the speed of (a) a physics student in Miami, Florida, at latitude 26 degrees
741
views
1
rank
Textbook Question
A typical laboratory centrifuge rotates at 4000 rpm. Test tubes have to be placed into a centrifuge very carefully because of the very large accelerations. a. What is the acceleration at the end of a test tube that is 10 cm from the axis of rotation?
765
views
1
rank