Mass of block= 20 kg moving to right, initial speed Vi=20 m/s , Height H=4m , ro
ID: 1433774 • Letter: M
Question
Mass of block= 20 kg moving to right, initial speed Vi=20 m/s, Height H=4m, rough surface= 0.2 of L=2m located before the spring. Block is stopped by spring of force K=200 N/m
A- determine W done on the block by force of friction
B- determine compression of spring X
C- determine energy stored by spring when it is compressed the distance you obtained in part B
Explain
The diagram above (not drawn to scale) shows a block of mass m = 20 kg moving to the The height of the inclined is h = 4m. All surfaces are smooth except for a rough surface (p-O 2) of length the spring. The block is stopped by a spring of force constant k 200 N/m. right with an initial speed of vo-20ms. L = 2m located before 3 A) Determine the work done on the block by the force of friction. B) Use energy considerations to determine the compression of the spring XExplanation / Answer
Here,
m = 20 Kg
vi = 20 m/s
H = 4 m
u = 0.2
L = 2 m
k = 200 N/m
a)
work done by the frictional force = - force * distance
work done by the frictional force = - u * m * g * L
work done by the frictional force = -0.2 * 20 * 9.8 * 2
work done by the frictional force = -78.4 J
b)
Using conservation of energy
0.5 * k * x^2 - work done by friction + m * g * H = 0.5 * m * vi^2
0.5 * 200 * x^2 + 78.4 + 20 * 9.8 * 4 = 0.5 * 20 * 20^2
solving for x
x = 5.601 m
the spring is compressed by 5.601 m
C)
energy stored in the spring = 0.5 k * x^2
energy stored in the spring = 0.5 * 200 * 5.601^2
energy stored in the spring = 3137.6 J