Question

Develop an understanding of lever arm Activity 1: Observing the effects of changing the Lever arm for a rotating body DEPARTMENT OF EDUCATION AND KNOWLEDGE Materials Required: Textbook, string, glue tack, tape. You must do the following activity turns to confirm the accuracy of your observations. pe. You must do the following activity in pairs taking Make your book stand on your desk so that the cover opens and closes like a door 2. Wrap one end of the threadin glue tack and sticke it to your book (secure with tape) mimos pictures shown one by one. 3. write your observations as one of the following choices al No effect b Some effect and c) Maxamum effect. Sample Problem: Barbara exerts a force on the outer edge of a door that is 76 cm wide at an angle of 300. What is the lever arm of the force?

Answer 1

the effort that is needed to open the door stays the ame : 14 уси « extesi w = {m , не dоох ші open more quickly. let us assume the work that you need to do is w..cto open the door). now this worly depends on the force with which you foush the knob and how far the knof Es from the hinge. Equations have been mentioned in the answer Coming to why it is easir to open the door when the knot is far is because the distance, a, between the hinge and knot is more. The Product of the force require of to open the door F and of is the worh needed, tie Fxd=W lalhen the knob & closer, d is smaller than What it was let call this b. since, bed, FXD < Fxd . This means As you go close you need more force to apply same hinge CR) opening the doos equi; Torque (t) = Force (F) & Distance from the T=F&R] T = FR sino it angle & will increase the value of Torque will Encreases

Barbara exests a force on the outer edge of the door il 76cm = 0.76 n. angle & ' = 30° T= Force (F) x distance (d) T = f d sino T = F x 0.76X sinsoo T = FX 0176x1 T=Fx0.038 Nm Torque = 0.038F Nml