# Physics Block and ramp

A crate of mass 0.812 kg is placed on a rough incline of an angle 35.3 degrees. Near the base of the incline is a spring of spring constant 1140 N/m. The mass is pressed against the spring a distance x and released. It moves up the slope 0.169 meters from the compressed position before coming to a stop. If the coefficient of kinetic friction in 0.195, how far (m) was the spring compressed?

The correct answer is 0.0417 but I get .0369.

My work:

d=kx^2m/2mgsin35.3
.169m = ((1140 Nm)(x^2))/(2(.812 kg)(9.8 m/s^2)(.5778)

(.169m)(9.1967) = 1140 N/m(x^2)

x = sqr root .00136
= .0369

1. 👍 1
2. 👎 0
3. 👁 1,052
1. Potential energy in spring = (1/2)(1140)x^2
= 570 x^2

Energy change due to increase in altitude
= m g (.169) sin 35.3
= .812 (9.8)(.169) sin 35.3
= .777 Joules

Energy lost to friction = force*.169
= .195 m g cos 35.3 *.169
= .195 (.812)(9.8)(.169 cos 35.3)
= .214 Joules
so
570 x^2 = .777 + .214 = .991
x = .0417 meters

1. 👍 1
2. 👎 0
2. Thank you so much!!!! I get it.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Physics

A crate of fruit with a mass of 37.5 kg and a specific heat capacity of 3800 J/(kg⋅K) slides 7.60 m down a ramp inclined at an angle of 38.5 degrees below the horizontal. If the crate was at rest at the top of the incline and

asked by Physics on September 15, 2017
2. ### college physics

A man pushing a crate of mass m = 92.0 kg at a speed of v = 0.860 m/s encounters a rough horizontal surface of length = 0.65 m as in the figure below. If the coefficient of kinetic friction between the crate and rough surface is

asked by ann on November 21, 2011
3. ### Physics

The coefficient of static friction between the 3.00 kg crate and the 35.0 degree incline is .300. What minimum force must be applied to the crate from sliding down the incline?

asked by Dee on September 28, 2011
4. ### physics

A man pushing a crate of mass m = 92.0 kg at a speed of v = 0.875 m/s encounters a rough horizontal surface of length ℓ = 0.65 m as in the figure below. If the coefficient of kinetic friction between the crate and rough surface

asked by Ange on March 9, 2015
1. ### physics

1. A boy drags a wooden crate with a mass of 20 kg, a distance of 12 m, across a rough level floor at a constant speed of 1.50 m/s by pulling on the rope tied to the crate with a force of 50 N. The rope makes an angle of 25¡ã

asked by annie on October 24, 2011
2. ### Physics

A large crate filled with physics laboratory equipment must be moved up an incline onto a truck. 1. The crate is at rest on the incline. What can you say about the force of friction acting on the crate? a. The friction force point

asked by Nicole on September 22, 2008
3. ### Physics

To move a large crate across a rough floor, you push on it with a force at an angle of 21 below the horizontal, as shown in the figure. Find the acceleration of the crate if the applied force is 400 , the mass of the crate is 32

asked by Randy on March 6, 2011
4. ### physics

A 10 kg crate is pulled up a rough incline with an initial speed of 1.5 m/s. The pulling force is 100 N parallel to the incline, which makes an angle of 20 degrees with the horizontal. If the coefficient of kinetic friction is .40

asked by wency siatula on May 3, 2016
1. ### physics

A crate of mass m (=40 kg) is placed at rest on a (frictionless) inclined plane, which has an angle (= 30o) above horizontal. a.) The force of gravity on the crate is: b.) The normal force on the crate is: size: N c.) The net

asked by kelsey on September 23, 2008
2. ### Physics

The coefficient of static friction between the m = 3.20-kg crate and the 35.0° incline of the figure below is 0.260. What minimum force vector F must be applied to the crate perpendicular to the incline to prevent the crate from

asked by James on March 4, 2014
3. ### physics newtons laws 3

The coefficient of static friction between the m = 3.20 kg crate and the 35.0° incline of Figure P4.41 is 0.260. What minimum force must be applied to the crate perpendicular to the incline to prevent the crate from sliding down

asked by luc on October 18, 2009
4. ### Physics

The coefficient of static friction between the m = 2.95-kg crate and the 35.0° incline is 0.345. What minimum force must be applied to the crate perpendicular to the incline to prevent the crate from sliding down the incline?

asked by Lala on October 26, 2011