Box-1 . . . D
Box-2 . . . B
Box-3 . . . A
Box-4 . . . C
Answer:
the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward
Explanation:
Is this exercise in kinematics
v = v₀ - g t
where g is the acceleration of the ball, which is created by the attraction of the ball to the Earth.
At the highest point
velocity must be zero.
The acceleration depends on the Earth therefore it is constant at this point and with a downward direction.
The force of the earth on the ball is towards the center of the Earth, that is, down
all other alternatives are wrong
Answer:
2123.55 $/hr
Explanation:
Given parameters are:
KV
L = 143 km
I = 500 A
So, we will find the voltage potential provided for the city as:
kV
kV
Then, we will find dissipated power because of the resistive loss on the transmission line as:
W
Since the charge of plant is not given for electric energy, let's assume it randomly as 
Then, we will find the price of energy transmitted to the city as:
$/hr
To calculate money per hour saved by increasing the electric potential of the power plant:
Finally,
$/hr
The amount of money saved per hour = 
$/hr
Note: For different value of the price of energy, it just can be substituted in the equations above, and proper result can be found accordingly.
Answer: 1.59 sec
Explanation:
The kinetic energy contained in the rotation of the cylinder is 1/2 m v^2
The kinetic energy of translation is also 1/2 m v^2
so the total energy is m v^2
The force applied is mg sin (theta)
= m x 9.8 x 1/2
= 4.9 m
Now equate
F x d = m v^2
4.9 m x 3.1 = m v^2
v^2 = 4.9 x 3.1
v = sqrt(4.9 x 3.1) = 3.9 m/s
Acceleration.
V^2 = 2 a s
4.9 x 3.1 = 2 x a x 3.1
4.9 = 2 a
a = 2.45 m/s^2
Time
T = v/a
= 3.9/2.45
= 1.59 sec
