Answer:
a) 1.75s b) 17.2 m/s (down)
Explanation:
d1= 15m d2= 0m (because it hits ground)
a= -9.81 m/s^2 t=???
Equation
the triangle means change in so d2-d1
Δd= v1 * t + 1/2 * a * t^2
0m-15m= v1*t + 1/2 a t^2
-15 m= 0m/s*t (goes away) + 1/2* a *t^2
-15mx2= t^2
-15mx2/a= t^2
Square root (-30/-9.81m/s^2)
t=1.75 s
b) now v2!!
Im going to use v2= v1 + a*t
v2= 0m/s + -9.81 x 1.75s
v2 = -17.2 m/s or you can say 17.2 m/s down!!!
Answer:

Explanation:
As we know that the acceleration of a point on the rim of the disc is in two directions
1) tangential acceleration which is given as

2) Centripetal acceleration

here we know that


now we know that net linear acceleration is given as

so we have


Answer:
The magnitude of the charge on each sphere is 0.135 μC
Explanation:
Given that,
Mass = 1.0
Distance = 2.0 cm
Acceleration = 414 m/s²
We need to calculate the magnitude of charge
Using newton's second law


Put the value of F

Put the value into the formula





Hence, The magnitude of the charge on each sphere is 0.135μC.
A hole, and people die if they fall in there.