Rifle and Bullet A rifle is aimed horizontally at a target 2

Rifle and Bullet A rifle is aimed horizontally at a target 27 m away. The bullet hits the target 2.2 cm below the aiming point. Neglect air resistance. What is the bullet\'s time of flight? s What is its speed as it emerges from the rifle? m/s Box of Cheerios Registered In Fig 6-55, a box of Cheerios Registered and a box of Wheaties Registered are accelerated across a horizontal surface by a horizontal force vector F applied to the Cheerios Registered box. The magnitude of the frictional force on the Cheerios Registered box is 2.5 N, and the magnitude of the frictional force on the Wheaties Registered box is 4.0 N. If the magnitude of vector F is 12 N, what is the magnitude of the force on the Wheaties Registered box from the Cheerios Registered box? N

Solution

horizontal distance: x =v0*t = 27

the time t is calculated as follows:

            y = -1/2*g*t^2= -0.022
            t = 0.067 s

thus the speed is,

     v0 = 27/t = 27/0.067 = 402.95 m/s

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frictional force: F_f = 2.5 + 4 = 6.5 N

net force on the boxes: F = 12 - 6.5 = 5.5 N

acceleration of the two boxes:

        a = F / M = 5.5 /(1 + 3) = 1.375 m/s²

net force on the wheaties box:

         F_W =m_W a = 3*1.375 = 4.125 N

force of cheerios box onwheaties box: F_CW = 4.125 + 4 = 8.125 N

Total force on cheerios box: F = 12 - 8.125 = 3.875 N

Net force on cheerios box = 3.875- 2.5 = 1.375 N