Can someone please work these step-by-step. I have the answers but needing to kn
ID: 1873897 • Letter: C
Question
Can someone please work these step-by-step. I have the answers but needing to know how to work them.
5. A hammer is dropped from the top of a tower that is 400 m high. If we neglect air resistance so that the only force on the hammer is gravity, with what velocity does the hammer strike the ground? 6. A cowboy shoots a bullet straight up into the air with an initial speed of 800 m/s. If the bullet is in free fall the entire time after leaving the gun, how long does it take the bullet to return to the ground? 7. A baseball is thrown horizontally from the top of a 11.0 m tower with an initial speed of 40.0 m/s. How far away is the ball from the base of the tower when it strikes the ground? 8. A circus performer is shot out of a cannon on the ground and needs to hit a paper target that is placed 8.0 m horizontally away from the cannon and 6.0 m above the ground. The performer needs to hit the target at the peak of his trajectory. At what initial speed and at what angle relative to the ground should the performer be shot out of the c annon? 9. While on an clevator, Melissa's apparert weight is 500 N. Her true weight is 560 N. What was the magnitude and dircction of Melissa's acceleration on the elevator?Explanation / Answer
5. a = - 9.8 m/s^2
vi = 0
and Applying vf^2 - vi^2 = 2 a (yf - yi)
v^2 - 0^2 = 2(-9.8)(0 - 400)
v = +-88.5 m/s
velocity will be downward.
v = -88.5 m/s
6. when it come back then yi = yf = 0
yf - yi = v0y t + ay t^2 / 2
0 - 0 = 800 t + (-9.8)(t^2 / 2)
t = 163.3 sec
7. yf - yi = v0y t + ay t^2 / 2
0 - 11 = 0 - 9.8 t^2 / 2
t = 1.498 sec
x = (v0x) t = 40 x 1.498 = 60 m