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5 votes
5 votes
19 point please please answer right need help

Block on an incline
A block of mass m1 = 3.9 kg on a smooth inclined plane of angle 38is connected by a cord over a small frictionless
pulley to a second block of mass m2 = 2.6 kg hanging vertically. Take the positive direction up the incline and use 9.81
m/s2 for g.
What is the tension in the cord to the nearest whole number?

User TigerTrussell
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2.5k points

1 Answer

10 votes
10 votes

Step-by-step explanation:

We can write Newton's 2nd law as applied to the sliding mass
m_1 as


T - m_1g\sin38 = m_1a\:\:\:\:\:\:\:(1)

For the hanging mass
m_2, we can write NSL as


T - m_2g = -m_2a\:\:\:\:\:\:\:(2)

We need to solve for a first before we can solve the tension T. So combining Eqns(1) & (2), we get


(m_1 + m_2)a = m_2g - m_1g\sin38

or


a = \left((m_2 - m_1\sin38)/(m_1 + m_2)\right)g


\:\:\:\:= 0.30\:\text{m/s}^2

Using this value for the acceleration on Eqn(2), we find that the tension T is


T = m_2(g - a) = (2.6\:\text{kg})(9.51\:\text{m/s}^2)


\:\:\:\:=24.7\:\text{N}

User Polochon
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2.4k points