1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Velocity attained by sled

  1. Oct 18, 2003 #1
    OK i'm stuk on a physics question involving Newton's Laws of motion.


    Boy gives his sister ride on sled by exerting force of 300 N[E].
    Frictional resistance amounts to 200 N. If sister and sled have combined mass of 50 kg, and if boy starts from rest and pushes for 5 sec., find:

    a) the sled's acceleration
    b) velocity attained by sled in 5 sec.
    c) distance travelled by sled in 5 sec.

    PLZ try to help and show step by step solutions

    Reply ASAP thanx:smile:
  2. jcsd
  3. Oct 18, 2003 #2


    User Avatar
    Science Advisor
    Gold Member

    It's not the policy here to do peoples homewrok, but I'll give you the relevant formulae:

    F = ma, v = u + at, s = ½(u + v)t

    F is force, m is mass, a is acceleration ,v is final velocity, u is intial velocity, s is displacemnet and t is time.
  4. Oct 19, 2003 #3

    Wait, how do we find initial velocity?

    Thanx for help.
  5. Oct 19, 2003 #4


    User Avatar
    Staff Emeritus
    Science Advisor

    We don't. But since the problem asked for the "velocity attained" (i.e. the increase in velocity), we can take it to be 0- that way the final velocity WILL be the increase in velocity.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?