Additional Mathematics question

• amaths

  10 Feb 09, 00:38

  Hi, would be grateful if anyone out there can provide the proof to the following question:

  The speed v m/s of a particle travelling from A to B, at time t seconds after leaving A, is v=10t-t^2.

  The particle starts from rest at A and comes to rest at B. Prove that the particle has a speed of 5 m/s or greater for exactly 4 <!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> √5 (ie, 4*(5^0.5)) seconds.

   

  Thanks and cheers.

   

• amaths

  10 Feb 09, 00:47

  Hi, sorry, not sure what went wrong above. Here is the question again. Thanks and cheers. ==== Hi, would be grateful if anyone out there can provide the proof to the following question: The speed v m/s of a particle travelling from A to B, at time t seconds after leaving A, is v=10t-t^2. The particle starts from rest at A and comes to rest at B. Prove that the particle has a speed of 5 m/s or greater for exactly 4*(5^0.5) seconds. ====