physics

A block of mass 12 kg starts from rest and slides a distance of 7 m down an inclined plane making an angle of 40◦ with the horizontal. The coefficient of sliding friction between block and plane is 0.4. The acceleration of gravity is 9.8 m/s2 . What is the net force on the block along the incline? Answer in units of N.
029 (part 2 of 3) 10.0 points What is the speed of the block after sliding 7 m? Answer in units of m/s.
030 (part 3 of 3) 10.0 points What would be its speed if friction were negligible? Answer in units of m/s.

  1. 👍 0
  2. 👎 0
  3. 👁 712
asked by Zugey

  1. M*g = 12 * 9.8 = 117.6 N. = Wt. of block.

    Fp = 117.6*sin40 = 75.6 N. = Force parallel to incline.

    Fn = 117.6*Cos40 = 90.1 N. = Normal force.

    Fk = u*Fn = o.4 * 90.1 = 36.0 N = Force of kinetic friction.

    A. Fnet = Fp-Fk = 75.6 - 36.0 = 39.6 N. = Net force.

    B. Fnet = M*a.
    39.6 = 12*a, a = 3.3 m/s^2.

    V^2 = Vo^2 + 2a*d. = 0 + 2*3.3*7 = 46.2
    V = 6.8 m/s.

    C. Fnet = Fp-Fk = 75.6-0 = 75.6 N.

    Fnet = M*a.
    75.6 = 12a, a = 6.3 m/s^2.

    V^2 = Vo^2 + 2a*d = 0 + 2*6.3*7 = 88.2,
    V = 9.4 m/s.

    1. 👍 0
    2. 👎 0
    posted by Henry

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    A 3.00-kg block starts from rest at the top of a 25.5° incline and slides 2.00 m down the incline in 1.75 s. (a) Find the acceleration of the block. m/s2 (b) Find the coefficient of kinetic friction between the block and the

    asked by Anonymous on October 23, 2013

  2. Impulse and Momentum

    A bullet of mass m is fired at speed v0 into a wooden block of mass M. The bullet instantaneously comes to rest in the block. The block with the embedded bullet slides along a horizontal surface with a coefficient of kinetic

    asked by Jennifer on March 1, 2015

  3. Physics

    A dockworker applies a constant horizontal force of 79.0 N to a block of ice on a smooth horizontal floor. The frictional force is negligible. The block starts from rest and moves a distance 13.0 m in a time 4.50 s. What is the

    asked by Jake on January 31, 2011

  4. physics

    a block with a mass of 3.7 kg slides with a speed of 2.2 m/s on a frictionless surface. the block runs into a stationary spring and compresses it a certain distance before coming to rest. what is the compression distances, given

    asked by Ty on February 11, 2014

  5. Physics

    An 8.70 kg block slides with an initial speed of 1.56 m/s **down** a ramp inclined at an angle of 28.4 with the horizontal. The coefficient of kinetic friction between the block and the ramp is 0.62. Use energy conservation to

    asked by AfterLife on July 16, 2011

  1. physics

    A block of mass 3kg starts from rest and slides down a surface, which corresponds to a quarter of a circle of 1.6m radius. a) if the curved surface is smooth, calculate the speed of the block at the bottom. b) if the block 's

    asked by gourav on March 18, 2015

  2. Physics

    Block 1 of mass m1 slides from rest along a frictionless ramp from height h and then collides with stationary block 2, which has mass m2 = 3m1. After the collision, block 2 slides into a region where the coefficient of kinetic

    asked by Isabel on November 1, 2011

  3. cary collage

    "A 2.5-kg block slides down a 25 degree inclined plane with constant acceleration. The block starts from rest at the top. At the bottom, its velocity reaches 0.65 m/s. The length of the incline is 1.6m. a) What is the acceleration

    asked by sahan on September 27, 2010

  4. Physics

    A wooden block of mass m = 9 kg starts from rest on an inclined plane sloped at an angle θ from the horizontal. The block is originally located 5m from the bottom of the plane. If the block, undergoing constant acceleration down

    asked by Mike on February 3, 2013

  5. Physics (Algebra-based)

    A block starts at rest and slides down a frictionless track except for a small rough area on a horizontal section of the track.It leaves the track horizontally, flies through the air, and subsequently strikes the ground. gravity=

    asked by Becky on April 6, 2013

  6. physics

    A 5.4 kg block slides down an inclined plane that makes an angle of 38 with the horizontal. Starting from rest, the block slides a distance of 2.5 m in 5.3 s. The acceleration of gravity is 9.81 m/s2 . Find the coefficient of

    asked by Sara on March 14, 2011

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