Physics

posted by .

A 15 kg box sits on a horizontal force.

the coefficient of static fricition between the box and the surface is 0.70. if a force P is exerted on the box at an angle directed 37 degrees below the horizontal, what must be the magnitude of P to get the box moving??

  • Physics -

    force down = 15 * 9.8 + P sin 37
    force horizontal = P cos 37
    0.7 (15 + P sin 37) = P cos 37

  • Physics -

    How can a box sit on a force? Do you mean that it sits on a horizontal surface?

    The vertical force applied to the surface by the box is
    15*g + P*sin37.

    The maximum friction force (which starts it moving) is
    Ff = 0.70(15*g + P*sin37)
    This must equal the horizontal component of P, so
    Pcos37 = 15*g + P*sin37
    P(cos37 - sin37) = 15 g
    P = (15/0.1968)*g = 747 N

  • Physics -

    i mean horizontal surface not horizontal force..sorry..

  • Physics -

    I believe Damon neglected to include a g term when considering the weight of the mass. Otherwise, we agree.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    A wooden box with a mass of 10.0kg rests on a ramp that is inclined at an angle of 25 degrees to the horizontal. A rope attatched to the box runs parallel to the ramp and then passes over a frictionless pulley. A bucket with a mass …
  2. Physics help!

    A box of books weighing 323 N is shoved across the floor by a force of 477 N exerted downward at an angle of 35° below the horizontal. (a) If μk between the box and the floor is 0.51, how long does it take to move the box 4.80 …
  3. Physics

    A box with a mass of 7.00 kg is at rest on a ramp that is at an angle of 20 degrees with the horizontal. The coefficient of static friction between the box and the ramp is 0.800. Use g = 9.80 m/s2. You now want to make the box move …
  4. Physics

    A 15 kg box sits on a horizontal force. the coefficient of static fricition between the box and the surface is 0.70. if a force P is exerted on the box at an angle directed 37 degrees below the horizontal, what must be the magnitude …
  5. Physics

    ohh sorry, in my first question... A 15 kg box sits on a horizontal FORCE. the coefficient of static fricition between the box and the surface is 0.70. if a force P is exerted on the box at an angle directed 37 degrees below the horizontal, …
  6. Physics

    A 50.0-kg box is resting on a horizontal floor. A force of 250 N directed at an angle of 20.7° below the horizontal is applied to the box. The coefficient of kinetic friction between the box and the surface is 0.300. What is the acceleration …
  7. physics

    A box of books weighing 314 N is shoved across the floor by a force of 475 N exerted downward at an angle of 35° below the horizontal. (a) If μk between the box and the floor is 0.53, how long does it take to move the box 5.00 …
  8. simple physics

    You push downward on a box at an angle 25° below the horizontal with a force of 750 N. If the box is on a flat horizontal surface for which the coefficient of static friction with the box is 0.73, what is the mass of the heaviest …
  9. Physics

    A box of books weighing 337 N is shoved across the floor by a force of 467 N exerted downward at an angle of 35° below the horizontal. (a) If μk between the box and the floor is 0.56, how long does it take to move the box 4.00 …
  10. Physical Science

    A 50.0-kg box is resting on a horizontal floor. A force of 250 N directed at an angle of 26.0° below the horizontal is applied to the box. What is the minimum coefficient of static friction between the box and the surface required …

More Similar Questions