Question
1: One dime an access code for this class or date you will no longer be able to see your WebAssign assignments or grades An attacker at the base of a castle wall 3,75 m high throws a rock st raight up with speed 9.00 m/s from a height of 1.45 m above the ground (a) will the rock reach the top of the wall7 O Yes (b) If so, what is its speed at the top? If not, what initial speed must it have to reach the top? m/s (c) Find the change in speed of a rock thrown stralght down from the top of the wall at an initial speed of 9.00 m/s and moving between the same two points m/s (d) Does the change in speed of the downward-moving rock agree with the magnitude of the speed change of the rock moving upward between the O No
Explanation / Answer
here,
h1 = 3.75 m
h0 = 1.45 m
a)
the maximum height reached by ball , h = h0 + u^2/2g
h = 1.45 + 9^2/(2*9.8)
h = 5.63 m
so it will reach the Top
b)
the speed at top be v
v^2 - u^2 = - 2 * g * s
v^2 - 9^2 = - 2 * 9.81 * (3.75 - 1.45)
v = 6 m/s
c)
change in speed , dv = v - u = 3 m/s
d)
Yes, it agrees
e)
because the gravity remains in the same direction and the height difference is also same