Answer:The sun, earth, and moon are held together by gravity, and they interact in lots of ways.
- The tides are another interaction in the sun-earth-moon system. The tides happen because the moon and sun pull on the oceans, causing them to rise and fall each day. The moon has a bigger effect than the sun because it is closer.
Consider velocity to the right as positive.
First mass:
m₁ = 4.0 kg
v₁ = 2.0 m/s to the right
Second mass:
m₂ = 8.0 kg
v₂ = -3.0 m/s to the left
Total momentum of the system is
P = m₁v₁ + m₂v₂
= 4*2 + 8*(-3)
= -16 (kg-m)/s
Let v (m/s) be the velocity of the center of mass of the 2-block system.
Because momentum of the system is preserved, therefore
(m₁+m₂)v= -16
(4+8 kg)*(v m/s) = -16 (kg-m)/s
v = -1.333 m/s
Answer:
The center of mass is moving at 1.33 m/s to the left.
Power = Work/time
Work= energy
Potential energy =mxgxh
Power=mxgxh/t
Power=68x10x7/9
Power=529 watts
Answer:
Choice d. Approximately 
of the volume of this iceberg would be submerged.
Explanation:
Let 
denote the total volume of this iceberg. Let 
denote the volume of the portion that is under the liquid.
The mass of that iceberg would be 
. Let 
denote the gravitational field strength (
near the surface of the earth.) The weight of that iceberg would be: 
.
If the iceberg is going to be lifted out of the sea, it would take water with volume to fill the space that the iceberg has previously taken. The mass of that much sea water would be 
.
Archimedes' Principle suggests that the weight of that much water will be exactly equal to the buoyancy on the iceberg. By Archimedes' Principle:
.
The buoyancy on the iceberg should balance the weight of this iceberg. In other words:
.
Rearrange this equation to find the ratio between and :
.
In other words, of the volume of this iceberg would have been submerged for buoyancy to balance the weight of this iceberg.
