A block of mass m = 150 kg rests against a spring with a spring constant of k = 880 N/m on an inclined plane which makes an angle of θ degrees with the horizontal. Assume the spring has been compressed a distance d from its neutral position. Refer to the figure. show answer No Attempt 25%
Part (a) Set your coordinates to have the x-axis along the surface of the plane, with up the plane as positive, and the y-axis normal to the plane, with out of the plane as positive. Enter an expression for the normal force, FN, that the plane exerts on the block (in the y-direction) in terms of defined quantities and g. 25%
Part (b) Denoting the coefficient of static friction by μs, write an expression for the sum of the forces in the x-direction just before the block begins to slide up the inclined plane. Use defined quantities and g in your expression ΣFx = 25%
Part (c) Assuming the plane is frictionless, what will the angle of the plane be, in degrees, if the spring is compressed by gravity a distance 0.1 m? 25%
Part (d) Assuming θ = 45 degrees and the surface is frictionless, how far will the spring be compressed, d in meters?

Respuesta :

Answer:

Explanation:

given

spring constant k = 880 N/m

mass m = 150 kg

Normal force will be equal to the component of weight of mass m which is perpendicular to the inclined surface

= mgcosθ

So normal force

FN = mgcosθ j , as it acts in out of plane direction .

b )

Fricrion force acting in upward direction = μs mgcosθ

component of weight acting in downward direction = mgsinθ

restoring force by spring on block in downward direction

= kd

= 880d

F( total ) = (μs mgcosθ -  mgsinθ -  880d )i

c )  

for balance

mgsinθ =  kd

sinθ = kd / mg

= 880 x .1 / 150 x 9.8

= 88 / 1470

.0598

θ = 3.4 degree

d )

d = mgsinθ / k

150 x 9.8 sin45 / 880

= 1.18 m

The traslational equilibrium condition and Hooke's law allow us to find the results for the problem is static equilibrium are:

a) The expression for the normal force is: N = m g cos θ

b) The expression for the forces in the x-axis is:  

        kx + mg (sin θ - mg cos θ)=0

c) The angle of the plane is θ = 3.4º

d) For angle  of 45º the compression of the spring is: x = 1.18 m

Newton's second law gives a relationship between the force, the mass and the acceleration of the bodies, in the special case that the acceleration is zero, it reduces to the equilibrium condition.

        Σ F = 0

Where bold letters indicate vectors, F is the external force

The reference system with respect to which to carry out the measurements and decomposition of the vector is indicated in the exercise, where the x-axis is parallel to the plane and is upwards is positive, the y=axis is perpendicular to the plane

The free-body diagram is a representation of the forces without the details of the bodies. In the attachment we can see a free-body diagram of this system.

Let's write the equilibrium condition for each exercise

a) y-axis

          N- W_y = 0

          N = [tex]W_y[/tex]

Let's use trigonometry to find the components of the weight

          sin θ θ = [tex]\frac{W_x}{W}[/tex]

          cos θ = [tex]\frac{W_y}{W}[/tex]

          Wₓ = W sin θ

          W_y = W cos θ

We substitute

           N = m g cos θ

           

b) x-axis

Just before starting to move the acceleration is zero  

            [tex]F_e[/tex]  - fr - Wₓ = 0

The friction force that is given by the expression

            fr = μ N

We substitute

            fr = μ mg cos θ

Hooke's law states that the force recovered from a spring is proportional to the displacement from equilibrium position

            [tex]F_e[/tex] = - kx

We substitute

            kx -  μ mg cos θ - m g sin θ = 0        (1)

c) In this part they indicate that the friction force is zero and ask how much the angle of inclination is worth

        kx - m g sin θ = 0

        θ = sin⁻¹ [tex]\frac{kx}{mg}[/tex]

        θ = sin⁻¹  ( [tex]\frac{880 \ 0.1}{150 \ 9.8}[/tex])

         θ = 3.4º

d) How much the spring is compressed for an angle of 45º

We write equation 1

             kx - m g sin θ = 0

             x = [tex]\frac{mg}{k} \ sin \theta[/tex]

             x = [tex]\frac{150 \ 9.8 }{880} \ sin 45[/tex]

             x = 1.18 m

In conclusion, using the traslational equilibrium condition and Hooke's law we can find that the results for the problem is equilibrium are:

a) The expression for the normal force is: N = m g cos tea

b) The expression for the forces in the x- axis is:

          kx + mg (sin θ - μ cos θ) = 0

c) The angle of the plane is θ = 3.4º

d) For angle   θ = 45º the compression of the spring is: x = 1.18 m

Learn more here: brainly.com/question/13861141

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