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3 years ago

A 2,100 kg car is lifted by a pulley. If the cable breaks at 4.50 m, what is the velocity of the car when it hits the ground

1 answer:

4 0

The problem involves the conversion of potential energy to kinetic energy as the object falls from rest. Energy is conserved, so the equation used is:

PEi + KEi = PEf + KEf

Since the object is falling from rest, the initial kinetic energy is zero. Also, since the object hits the ground at its final position, the final potential energy is zero. This leaves:

PEi = KEf
mgh = 1/2 mv^2

*cancel out mass on both sides of the equation

gh = 0.5v^2
v = sqrt(2gh) = sqrt(2*9.81*4.5) = 9.40 m/s --> final ans.

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3 years ago

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Alexxandr [17]

Explanation:

It is given that,

Mass of the soccer ball, m = 0.425 kg

Speed of the ball, u = 15 m/s

Angle with horizontal, $\theta=33^{\circ}$

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Part A,

The x component of the soccer ball's change in momentum is given by :

$\Delta p_x=mv\ cos\theta$

$\Delta p_x=0.425\times 15\ cos(33)$

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The y component of the soccer ball's change in momentum is given by :

$\Delta p_y=mv\ sin\theta$

$\Delta p_y=0.425\times 15\ sin(33)$

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4 years ago