Calculus-derivatives

posted by .

Explain how to do these questions~

1. An object moves in a straight line with its position at time t seconds given by s(t) = 3-2t+t^2, where s is the measured in metres. At what time is the object not moving?

2. Determine the coordinates of the point(s) on the graph of y=3x- 1/x at which the slope of the tangent is 7.

  • Calculus-derivatives -

    s=3-2t+t^2
    ds/dt=-2+2t

    when it is not moving, ds/dt =0, solve for t.

    y=(3x-1)/x= 3-1/x

    dy/dx=+1/x^2

    if slope is 7, then
    7=1/x^2
    x^2=1/7
    x= sqrt(1/7)
    y=(3x-1)/x solve for y.

  • Calculus-derivatives -

    For number one we find the derivative of 3-2t+t^2

    wouldn't that be t-2?

  • Calculus-derivatives -

    Oh crap nvm!

  • Calculus-derivatives -

    So for number 1 the answer is t=1

    -2+2t=0
    2t=2

    2/2=1

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. kinematics

    these are two similar kinematics maths question which i don't know. Please help! 1)A particle moves in a straight line so that its distance, s metres, from a fixed point O is given by s = 2t^3 - 3t^2 - 12t + 6, where t is the time …
  2. urgent calculus

    The position of a particle moving in a straight line is given by s(t) = 2sint - cost , from 0 to 2 pi where s is the displacement in metres and t is the time in seconds. Find the absolute max and absolute min displacements.
  3. calculus

    a particle moves along a number line measured in cm so that its position at time t sec is given by s=72/(t+2) +k, k is a constant and t>=0 seconds. (a) Find the instantaneous velocity of the particle at t=4 seconds (b) Find the …
  4. Calculus

    A particle moves in a straight line under a force such that its displacement s(t), in metres, at time t seconds, is given by s(t) = t3 − 5t2 + 3t +15 (i) Find the expression for the velocity of the particle. (ii) Find the time …
  5. calculus

    A particle moves in a straight line under a force such that its displacement s(t), in metres, at time t seconds, is given by s(t) = t3 − 5t2 + 3t +15 Find the time at which the particle is at rest?
  6. Calculus

    A particle moves along the x-axis so that at any time t, measured in seconds, its position is given by s(t) = 5cos(t) − sin(3t), measured in feet. What is the acceleration of the particle at time t = π seconds?
  7. maths

    A particle of mass 40 40kg moves in a straight line such that the force (in newtons) acting on it at time,t (in seconds) is given by, 160t^4-320t^2-360 at time t=0, v is given by v(0)=10, and its position x is given by x(0)=14. What …
  8. Maths, dynamics

    A particle of mass 45 kg moves in a straight line such that the force (in Newtons) acting on it at time t (in seconds) is given by 225t^4-90 t^2-225. If at time t = 0 its velocity, v , is given by v ( 0 ) = 2, and its position x (in …
  9. Calculus

    Suppose a certain object moves in a straight line with velocity v(t)= -2+t+3sin(pi t) where v is in meters per second and t is in seconds. Determine the net change in distance of the object from time t=0 to time t=6 seconds and find …
  10. Calculus

    1) A particle is moving along the x-axis so that its position at t ≥ 0 is given by s(t) = (t)In(2t). Find the acceleration of the particle when the velocity is first zero. 2) The driver of a car traveling at 50 ft/sec suddenly applies …

More Similar Questions