physics-speed

i need help with this one
thanks

A particle starts from rest and is acted on by a net force that does work at a rate that is proportional to the time t. The speed of the particle is proportional to:

a. sq. root t
b. t
c. t^2
d.1/sq. root t
e. 1/t



Work done is proportional to the integral of a constant times t. That means the work done is proportional to t^2. It will equal the final kinetic energy, which is proportional to v^2. Therefore v^2 is proportional to t^2, and v must be proportional to t.

  1. 👍
  2. 👎
  3. 👁
  1. i choose answer d.

    1. 👍
    2. 👎
  2. i got the same problem, and the answer is A. I have no idea why

    1. 👍
    2. 👎
  3. the answer is A
    work is proportional to t.
    work is the change in kinetic energy.
    then work is of the order of V^2.
    then V^2 is prop. to t.
    therefore, V is prop. to sq.root t

    1. 👍
    2. 👎
  4. Draw a sketch to show the force acting on the climber

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics

    At t= 0, a particle starts from rest at x= 0, y= 0, and moves in the xy plane with an acceleration ->a (vector) = (4.0ihat+ 3.0jhat)m/s^2. Assume t is in seconds. Determine the x component of velocity as a function of time t.

  2. physics

    A particle of mass 82 g and charge 80 µC is released from rest when it is 81 cm from a second particle of charge −24 µC. Determine the magnitude of the initial acceleration of the 82 g particle. Answer in units of m/s 2

  3. physics

    Two point charges of 48 nC and -45 nC are held fixed on an x axis, at the origin and at x = 77 cm, respectively. A particle with a charge of 69 μC is released from rest at x = 49 cm. If the initial acceleration of the particle

  4. physics

    Two forces, 1 = (3.85 − 2.85) N and 2 = (2.95 − 3.65) N, act on a particle of mass 2.10 kg that is initially at rest at coordinates (−2.30 m, −3.60 m). (a) What are the components of the particle's velocity at t = 11.8 s?

  1. Calculus

    The position of a particle moving on a horizontal line is given by s(t)=2t^3-15t^2+24t-5, where s is measured in feet and t in seconds. a: What is the initial position of the particle? b: What is the average velocity of the

  2. Physics

    A particle starts from the origin at t = 0 and moves along the positive x axis. A graph of the velocity of the particle as a function of the time is shown in the figure; the v-axis scale is set by vs = 7.0 m/s. (a) What is the

  3. Physics

    I need help with this question with explanation. Thanks A particle of mass m starts from rest at position x = 0 and time t = 0. It moves along the positive x-axis under the influence of a single force Fx = bt, where b is a

  4. Physics

    a particle moving in the xy plane has velocity components dx/dt =2t and dy/dt = 4. If the particle starts from the origin at t = 0,magnitude of its displacement at t=2 is

  1. Physics

    A particle of mass 5kg initially at rest is acted upon by two mutually perpendicular forces 12N And 15N.if the particle move in the direction OA,calculate the magnitude of the acceleration?

  2. Physics

    At t=0 a particle starts from rest at x=0, y=0 and moves in the xy plane with an acceleration a=(4.0i+3.0j)m/s^2. Determine (a) the x and y components of velocity, (b) the speed of the particle, and (c) the position of the

  3. physics

    A particle moving with a constant acceleration describes in the last second of it's motion 9/25th of the whole distance.of it starts from rest ,how long is the particle is in motion and through what distance does it move if it

  4. Calculus

    a particle starts at time t = 0 and moves along the x axis so that its position at any time t>= 0 is given by x(t) = ((t-1)^3)(2t-3) a.find the velocity of the particle at any time t>= 0 b. for what values of t is the velocity of

You can view more similar questions or ask a new question.