The path of an object looks like line, zigzag line and curve etc.
Uniform motion refers only to speed of the object. Speed is described by distance traveled by an object with time. Uniform motion i.e. speed conveys no information regarding the direction of the object.
If object continues to move in fixed direction, then path will look like the straight line. Otherwise with varying direction & uniform motion, there could be various paths like straight line, zigzag line, circle, curve and many more.
hope it helps u dear...
sounds like a homework problem
the method you should use is work done = force x distance.
assume the resitive force is constant when piercing the plank and the same for both planks.
work out energy to pierce plank/energy to pierce plank. use energy or work = fx d but remeber the f values are the same so you can cancel.
now you know the energies of the kes: ke to pierce /ke to pierce = same ratio as in 2. above.
ke /ke = (1mv^2) ()/(1mv^2) now assume mass is constant and cancel.
ke /ke = v^2 ()/(v2)
you know thr artionof the kes, you know v ^2()
you should be home and dry.
find the attachment
may be it's for you
straight line and...