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In a nutshell, a smaller rock is propelled into the air as a huge counterweight in the back falls down, effectively converting gravitational potential energy into kinetic energy for the rock and the weight. But, since the rock is smaller.. it is propelled at a much faster velocity! Let's say we wanted to hurl a 50 kg boulder at a castle wall 100 meters away. Our wooden structure for the trebuchet is 10 meters tall, so that is the maximum distance the counterweight can fall. Assuming the launch angle is a perfect 45 degrees, and the boulder is released from ground level, derive the needed mass of the counterweight that will give the boulder enough kinetic energy to reach the base of the castle walls. You may assume no energy is "lost" due to friction, and ALL the counterweight's gravitational potential energy is converted into the boulder's kinetic enerqy. (HINT: You will need to employ 2D kinematics to find the needed final velocity, then use that final velocity in an energy equation…

P4.7 For the scaled mechanism shown in figure P4.7, determine (a) the acceleration of point B (b) the sliding acceleration of point A2 with respect to point A4 use a complex numbers approach

In the figure below Atwood’s machine is drawn - two masses  and  hanging over a massive pulley of rotational inertia  and radius , connected by a massless unstretchable string. The string rolls on the pulley without slipping.a) Find the acceleration of the system and the tensions in the string on both sides of the pulley in terms of in terms of given variables.b) Why are the rope tensions on two sides of the pulley not the same? Explain it physically.c) Suppose mass    and the system is released from rest with the masses at equal heights. When mass  has descended a distance , find the velocity of each mass and the angular velocity of the pulley.[4***] A string is rolled around a cylinder(   kg) as shown in figure. A person pulls on the string, causing the cylinder to roll without slipping along the floor