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The figure below shows two blocks connected by a string of negligible mass passi

ID: 1436158 • Letter: T

Question

The figure below shows two blocks connected by a string of negligible mass passing over a frictionless pulley, m_1 = 5.4 kg and Theta = 12.0 degree . Assume that the incline is smooth. For what value of m_2 will the system be in equilibrium? If the block has to slide down the incline with an acceleration of 0.81 m/s^2, what should be the value of m_2? Kg Show My Work (Optional) A rifle bullet with a mass of 18.0 g traveling toward the right at 213 m/s strikes a large bag of sand and penetrates it to a depth of 22.9cm. Determine the magnitude and direction of the friction force (assumed constant) that acts on the bullet. Magnitude N direction

Explanation / Answer

On m2 gravity force (F1) = m2 g sin (12) = 2.03 m2

on m1 gravity force (F2) = m1 g = 52.92 N

For equilibrium

F1 = F2

2.03 m2 = 52.92

m2 = 26.06 N (answer a)

On m2
m2 g sin (12) -T = m2 x a ------------------------------(1)

on m1
T - m1 g = m1 x a

T = m1 (g+a) = 5.4 x (9.8 + .81) = 57.29 N

put it in ----------(1)

m2 g sin (12) -T = m2 x a

2.03 m2 - 57.29 = .81 m2

m2 = 46.95 kg (answer b)

Applying work energy theoram

W = change in KE

F.s = 1/2 m v^2 - 0

f x .229 = 1/2 x .018 x (213)^2

f = 1783.06 N