Salt water offers the least electrical resistance.
<u>Explanation:</u>
Least electrical resistance indicates that any material which readily allows the electric current through itself, and shows more conductivity.
Here pure water doesn't contain any ions, so it is a bad conductor.
Wood and glass are also bad conductors of electricity.
Salt water contains ions, which conducts electricity which means it shows least electrical resistance.
Explanation:
a) 
where 
is the distance of the mass 
from the axis of rotation. When the axis of rotation is placed at the end of the rod, the moment of inertia is due only to one mass. Therefore,
b) When the axis of rotation is placed on the center of the rod, the moment is due to both masses and the radius r is 1.5 m. Therefore,
Answer:
Approximately 
upwards (assuming that 
.)
Explanation:
External forces on this astronaut:
- Weight (gravitational attraction) from the earth (downwards,) and
- Normal force from the floor (upwards.)
Let 
denote the magnitude of the normal force on this astronaut from the floor. Since the direction of the normal force is opposite to the direction of the gravitational attraction, the magnitude of the net force on this astronaut would be:
.
Let 
denote the mass of this astronaut. The magnitude of the gravitational attraction on this astronaut would be 
.
Let 
denote the acceleration of this astronaut. The magnitude of the net force on this astronaut would be 
.
Rearrange to obtain an expression for the magnitude of the normal force on this astronaut:
.
Answer:
The speed of the block is 8.2 m/s
Explanation:
Given;
mass of block, m = 2.1 kg
height above the top of the spring, h = 5.5 m
First, we determine the spring constant based on the principle of conservation of potential energy
¹/₂Kx² = mg(h +x)
¹/₂K(0.25)² = 2.1 x 9.8(5.5 +0.25)
0.03125K = 118.335
K = 118.335 / 0.03125
K = 3786.72 N/m
Total energy stored in the block at rest is only potential energy given as:
E = U = mgh
U = 2.1 x 9.8 x 5.5 = 113.19 J
Work done in compressing the spring to 15.0 cm:
W = ¹/₂Kx² = ¹/₂ (3786.72)(0.15)² = 42.6 J
This is equal to elastic potential energy stored in the spring,
Then, kinetic energy of the spring is given as:
K.E = E - W
K.E = 113.19 J - 42.6 J
K.E = 70.59 J
To determine the speed of the block due to this energy:
KE = ¹/₂mv²
70.59 = ¹/₂ x 2.1 x v²
70.59 = 1.05v²
v² = 70.59 / 1.05
v² = 67.229
v = √67.229
v = 8.2 m/s
Answer:
It floats
Explanation:
Boats don't drown they row.
