Answer on Question #39802, Physics, Mechanics | Kinematics | Dynamics
Question:
An applied force of 200.0N gives a sled an acceleration of 2.00 m / s 2 2.00\mathrm{m/s^2} 2.00 m/ s 2 . If you place an additional 60kg mass on the sled, what will the acceleration be?
Answer:
Newton's second law of motion can be expressed in equation form as follows:
∑ F ⃗ = m a ⃗ \sum \vec{F} = m \vec{a} ∑ F = m a
Therefore:
F = m s a 0 F = m_s a_0 F = m s a 0
where m s m_s m s is mass of sled, a 0 a_0 a 0 is initial acceleration
With additional mass:
F = ( m s + m ) a F = (m_s + m) a F = ( m s + m ) a
From first equation:
m s = F a 0 m_s = \frac{F}{a_0} m s = a 0 F
And from second:
a = F m s + m = F F a 0 + m = a 0 1 + m a 0 F = 2 1 + 60 ⋅ 2 200 = 1.25 m s a = \frac{F}{m_s + m} = \frac{F}{\frac{F}{a_0} + m} = \frac{a_0}{1 + \frac{m a_0}{F}} = \frac{2}{1 + \frac{60 \cdot 2}{200}} = 1.25 \frac{m}{s} a = m s + m F = a 0 F + m F = 1 + F m a 0 a 0 = 1 + 200 60 ⋅ 2 2 = 1.25 s m
Answer: 1.25 m s 1.25 \frac{m}{s} 1.25 s m