Trusted by Students Everywhere
Why Choose Us?
0% AI Guarantee

Human-written only.

24/7 Support

Anytime, anywhere.

Plagiarism Free

100% Original.

Expert Tutors

Masters & PhDs.

100% Confidential

Your privacy matters.

On-Time Delivery

Never miss a deadline.

Learning Goal: To understand and apply the formula τ=Iα to rigid objects rotating about a fixed axis

Physics Jan 20, 2021

Learning Goal:

To understand and apply the formula τ=Iα to rigid objects rotating about a fixed axis.

To find the acceleration a of a particle of mass m, we use Newton's second law: F? net=ma? , where F? net is the net force acting on the particle.

To find the angular acceleration α of a rigid object rotating about a fixed axis, we can use a similar formula: τnet=Iα, where τnet=∑τ is the net torque acting on the object and I is its moment of  inertia.

In this problem, you will practice applying this formula to several situations involving angular acceleration. In all of these situations, two objects of masses m1 and m2 are attached to a seesaw. The seesaw is made of a bar that has length l and is pivoted so that it is free to rotate in the vertical plane without friction.Assume that the pivot is attached tot he center of the bar.

You are to find the angular acceleration of the seesaw when it is set in motion from the horizontal position. In all cases, assume that m1>m2.

Part A

Assume that the mass of the swing bar, as shown in the figure, is negligible.(Figure 1)

Find the magnitude of the angular acceleration α of the seesaw.

Express your answer in terms of some or all of the quantities m1, m2, l, as well as the acceleration due to gravity g.

 
   
α =

2(m1gm2g)1(m1+m2)

SubmitHintsMy AnswersGive UpReview Part

Incorrect; Try Again; 6 attempts remaining

Part B

In what direction will the seesaw rotate, and what will the sign of the angular acceleration be?

  The rotation is in the clockwise direction and the angular acceleration is positive.
  The rotation is in the clockwise direction and the angular acceleration is negative.
  The rotation is in the counterclockwise direction and the angular acceleration is positive.
  The rotation is in the counterclockwise direction and the angular acceleration is negative.

SubmitMy AnswersGive Up

Correct

Part C

Now consider a similar situation, except that now the swing bar itself has mass mbar.(Figure 2)

Find the magnitude of the angular acceleration α of the seesaw.

Express your answer in terms of some or all of the quantities m1, m2, mbar, l, as well as the acceleration due to gravity g.

 
   
α =  

SubmitHintsMy AnswersGive UpReview Part

Part D

In what direction will the seesaw rotate and what will the sign of the angular acceleration be?

In what direction will the seesaw rotate and what will the sign of the angular acceleration be?
  The rotation is in the clockwise direction and the angular acceleration is positive.
  The rotation is in the clockwise direction and the angular acceleration is negative.
  The rotation is in the counterclockwise direction and the angular acceleration is positive.
  The rotation is in the counterclockwise direction and the angular acceleration is negative.

Expert Solution

please see the attached file

Archived Solution
Unlocked Solution

You have full access to this solution. To save a copy with all formatting and attachments, use the button below.

Already a member? Sign In
Important Note: This solution is from our archive and has been purchased by others. Submitting it as-is may trigger plagiarism detection. Use it for reference only.

For ready-to-submit work, please order a fresh solution below.

Or get 100% fresh solution
Get Custom Quote
Secure Payment