Abaseball is thrown straight downward with an initial speed of 40 ft=s from the top of the washington monu- ment (555 ft high). how long does it take to reach the ground, and with what speed does the baseball strike the ground?

4.53 second, 195 ft/s

Explanation:

u = 50 ft/s

h = 555 ft

g = 32 ft/s^2

Let the time taken by the ball to reach the ground is t and the velocity of the ball as it hits the ground is v.

Use third equation of motion

v = 195 ft /s

Thus, the ball strikes the ground with velocity 195 ft/s.

Use first equation of motion

v = u + at

195 = 50 + 32 t

32 t = 145

t = 4.53 second

Thus, the ball reach the ground in 4.53 second.

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.