Physics

Q #2: (only other one I'm stuck on...)
A 10-kg ladder 2.5m long rests agaist a frictionless wall with its base on the floor 80cm from the wall. How much force does the top of the ladder exert on the wall?
I've found answers to similar questions on this site, but not close enough for me to figure this out. Thanks.

  1. 👍
  2. 👎
  3. 👁
  1. A = angle from floor to ladder
    get it from cos A = 0.80/2.5

    Take moments around base of ladder

    F * distance of top of ladder above floor
    = Weight of ladder * half distance of foot of ladder from wall

    F * 2.5 sin A = 10*9.8 * (2.5/2) cos A

    1. 👍
    2. 👎
  2. The answer is supposed to be 16.5N. I can't get it. Is angle A, 100deg? I took 0.80/2.5 = .32 and then cos (.32) = .9999deg.
    And then in the final equation, for
    sin A I got sin (100deg) = 98.4. This doesn't seem right.

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. geometry

    A 24 foot ladder forms a 76 degree angle with the ground. The top of the ladder rests against the building. To the nearest inch how high up the building does the ladder reach?

  2. Calculus (related rates)

    A ladder 13 meters long rests on horizontal ground and leans against a vertical wall. The foot of the ladder is pulled away from the wall at the rate of 0.4 m/sec. How fast is the top sliding down the wall when the foot of the

  3. Physics

    A ladder 10-m long and weighing 50 N rests against a smooth vertical wall. If the ladder is just on the verge of slipping when it makes a 50 degree angle with the ground, find the coefficient of static friction between the ladder

  4. Physics

    A 100-kg box is suspended from two ropes; the left one makes an angle of 20degrees with the vertical, and the other makes an angle of 40degrees. What is the tension in each rope. I think I've got the basics: I have Fx=T1(x) +

  1. math

    A ladder 10 m long rests on horizontal ground and leans against a vertical wall. The foot of the ladder is pulled away from the wall at 2 m/s. How fast is the top sliding down the wall when the foot of the ladder is 6m from the

  2. Physics

    A uniform ladder of length (L) and weight 100 N rests against a smooth vertical wall. The coefficient of static friction between the bottom of the ladder and the floor is 0.5. Find the minimum angle theta , which the ladder can

  3. geometry

    A ladder leaning against a vertical wall makes a angle of 75degree with the ground. If the foot of the ladder is 4 feet from the base of the wall, would this ladder be long enough for you to retrieve the suction dart that your

  4. physics-force

    A uniform ladder is 10 cm long and weights 400 N. It rests with ists upper end against a frictionless vertical wall. Its lower end rests on the ground and is prevented from slipping by a peg driven into the ground. The ladder

  1. Physics

    A uniform ladder 10.0m long and weighing 50.0N rests against a smooth vertical wall. If the ladder is just on the verge of slipping when it makes a 50 degree angle with the ground, find the coefficient of static friction between

  2. Algebra

    A 50ft ladder rests against a wall so that the top of the ladder is 48ft. from the ground. As you start climbing the ladder slips and the top of the ladder drops 8ft. How far does the bottom of the ladder slide away from the wall?

  3. Physics

    A 100N uniform ladder, 8.0m long, rests against a smooth vertical wall. the coefficient of static friction between ladder and the floor is 0.40. What minimum angle can the ladder make with the floor before it slips? im thinking

  4. Math

    a ladder that is 15 feet long leans against a house.the top of the ladder rests against the house at a height of 12 feet .how far from the building is the base of the ladder?

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