K (Q1) (Q2)/d^2 =
k : coulumb constant
Q1 : Charge on object 1
Q2 : Charge on object 2
d : distance between two charged object
Answer
given,
vertical speed of stone,v = 12 m/s
height of the cliff = 70 m
a) time taken by the stone to reach at the bottom of the cliff
We know that,
S = u t + 1/2 a t²
- 70 = 12 t - 0.5 x 9.8 t²
4.9 t² - 12 t - 70 = 0
solving the equation
t = 5.2 s (neglecting the negative value)
b) again using equation of motion
v = u + a t
v = 12 - 9.8 x 5.2
v = -38.96 m/s
ignoring the negative sign
magnitude of velocity is equal to 38.96 m/s
c) total distance travel by the stone
vertical distance covered by the stone
v² = u² + 2 g h
0 = 12² - 2 x 9.8 x h
h = 7.34 m
to reach the stone to the same level distance travel be doubled.
Total distance travel by the stone
H = h + h + 70
H = 7.34 x 2 + 70
H = 84.7 m.
8 phases. I really hope you get the right answer!
Answer:
You are given that the mass of the clock M is 95 kg.
This is true whether the clock is in motion or not.
Fs is the frictional force required to keep the clock from moving.
Thus Fk = uk W = uk M g the force required to move clock at constant speed. (the kinetic frictional force)
uk = 560 N / 931 N = .644 since the weight of the clock is 931 N (95 * 9.8)
us is the frictional force requited to start the clock moving
us = static frictional force = 650 / 931 -= .698
