A 1.0-kg cart and a 0.50-kg cart sit at different positions on a low-friction track. You push on the 1.0-kg cart with a constant 4.0-N force for 0.20 m. You then remove your hand, and the cart slides 0.35 m and strikes the 0.50-kg cart. What is the work done by you on the two-cart system? How far does the system's center of mass move while you are pushing the 1.0-kg cart? By what amount does your force change the kinetic energy of the system's center of mass?

Respuesta :

Answer:

a)[tex]W=0.8J[/tex]

b) [tex]d_t=0.20m[/tex]

c) [tex]\triangle K.E=0.267J[/tex]

Explanation:

From the question we are told that:

Mass of cart 1 [tex]M_1=1.0kg[/tex]

Mass of cart 1 [tex]M_2=0.05kg[/tex]

Force on  cart 1 [tex]F_1=4.0N[/tex]

Push Distance of cart 1 [tex]d_1=0.20m[/tex]

Slide Distance of cart 1 [tex]d_1'=0.35m[/tex]

a)

Generally the equation for work-done is mathematically given by

[tex]W=f*d\\W=4*0.20\\W=0.8J \\[/tex]

b)

The systems center of mass moved a net totally of (while being pushed)

Mass 1 =0.20m

Mass 2=0

Therefore

[tex]d_t=d_1+d_2[/tex]

[tex]d_t=0.20+0[/tex]

[tex]d_t=0.20m[/tex]

c)

Since work-done is equal to K.E energy of cart 1

Therefore

[tex]W=1/2mv^2[/tex]

[tex]V_1=\sqrt{\frac{W}{1/2m}}[/tex]

[tex]V_1=\sqrt{\frac{0.8}{1/2(1)}}[/tex]

[tex]V_1=1.264[/tex]

Therefore Kinetic energy before collision is

[tex]K.E_1=1/2mv^2[/tex]

[tex]K.E_1=1/2*1*1.264^2[/tex]

[tex]K.E_1=0.768[/tex]

Generally from the equation for conservation  of momentum the Velocity of cart 2 is mathematically given by

[tex]v_2=\frac{m_1V_1}{m_1+m_2}[/tex]

[tex]v_2=\frac{1*1.264}{1+0.5}[/tex]

[tex]V_2=0.842m/s[/tex]

Therefore the final K.E is mathematically given by

[tex]K.E_2=(1/2)(m_1+m_2)V_2^2[/tex]

[tex]K.E_2=1/2*(1.5)(0.842)^2[/tex]

[tex]K.E_2=0.531J[/tex]

Generally the Change in K.E is mathematically given by

[tex]\triangle K.E=K.E_1-K.E_2[/tex]

[tex]\triangle K.E=0.798-0.531[/tex]

[tex]\triangle K.E=0.267J[/tex]

Therefore the will force change the kinetic energy of the system's center of mass by

[tex]\triangle K.E=0.267J[/tex]

(a) The work done by you when you push the cart at a constant force is 0.8 J.

(b) The distance moved by the center mass of the two cart system is 0.23 m.

(c) The change in kinetic energy of the system center of mass is 0.271 J.

Work done by you

The work done by you when you push the cart at a constant force is calculated as follows;

W = Fd

W = 4 x 0.2

W = 0.8 J

Distance moved by the center mass of the two cart system

  • let the 0.5 kg mass be the reference mass at zero (0).

Xcm = (m₁x₁ + m₂x₂)/(m₁ + m₂)

Xcm = (0.5(0) + 1(0.35)) / (1 + 0.5)

Xcm = (0.35)/(1.5)

Xcm = 0.23 m

Initial velocity of the 1.0 kg mass

F = ma

a = F/m

a = (4)/1 = 4 m/s²

v² = u² + 2as

v² = 0 + 2(4)(0.2)

v² = 1.6

v = √1.6

v = 1.265 m/s

Final velocity of the masses

m₁u₁ + m₂u₂ = v(m₁ + m₂)

1(1.265) + 0 = v(1 + 0.5)

1.265 = 1.5v

v = 0.84 m/s

Change in kinetic energy

K.E(initial) = ¹/₂m₁u₁² + ¹/₂m₂u₂²

K.E(initial) = ¹/₂(1)(1.265)² + ¹/₂(0.5)(0) = 0.8 J

K.E(final) = ¹/₂(m₁ + m₂)v²

K.E(final) = ¹/₂(1 + 0.5)(0.84)²  = 0.529 J

Δ K.E = 0.8 J - 0.529 J = 0.271 J

Learn more about change in kinetic energy here: https://brainly.com/question/1932411

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