Answer:
Beryllium
Beryllium is an alkaline metallic element that is highly toxic. It is known for its sugary sweet taste and some of its common uses are in X-rays and fluorescent lights.
Beryllium : A very thorough and technical site about this mineral.
Chromite
Chromite is the ore of chromium and is a very hard metal, and diamond is the only thing harder. This hardness is what allows a chrome finish to take a high polish.
Chromite : This site talks about its history and characteristics.
Cobalt
Cobalt is famous for the incredible blue color it imparts to glass and pigment. It has been found in meteorites and is used in invisible ink. It is a brittle metal and resembles iron.
Cobalt : This site has photos, video, charts and physical and atomic descriptions.
Columbite-tantalite
Columbite-tantalite group is a mineral used widely in technology. Electronics, automotive systems and health products like the pacemaker need this mineral to operate. It is mined in Africa and has earned the name of Coltan over the last few years.
Columbite-tantalite : Information about its role in the world under the name 'Coltan'.
Copper
Copper is a common metal throughout the world. It is used for currency, jewelry, plumbing and to conduct electricity. It is a soft, orange-red metal.
Copper : This site talks about its properties, uses and makeup.
Explanation:
Hope that helps :)
Answer:
The boat moves away from the dock at 0.5 m/s.
Explanation:
Hi there!
Since no external forces are acting on the system boy-boat at the moment at which the boy lands on the boat, the momentum of the system is conserved (i.e. it remains constant).
The momentum of the system is calculated as the sum of the momentum of the boy plus the momentum of the boat. Before the boy lands on the boat, the momentum of the system is given by the momentum of the boy.
momentum of the system before the boy lands on the boat:
momentum of the boy + momentum of the boat
m1 · v1 + m2 · v2 = momentum of the system
Where:
m1 and v1: mass and velocity of the boy.
m2 and v2: mass and velocity of the boat.
Then:
50 kg · 2.0 m/s + 150 kg · 0 m/s = momentum of the system
momentum of the system = 100 kg m/s
After the boy lands on the boat, the momentum of the system will be equal to the momentum of the boat moving with the boy on it:
momentum of the system = (m1 + m2) · v (where v is the velocity of the boat).
100 kg m/s = (50 kg + 150 kg) · v
100 kg m/s / 200 kg = v
v = 0.5 m/s
The boat moves away from the dock at 0.5 m/s.
Answer:
The wheelbarrow's wheel and axle help the wheelbarrow to move without friction thus making it easier to push or pull. That's why it will be easier to lift a load in wheel barrow of the load is transferred towards the wheel.
Answer:
The answer to your question is given below.
Explanation:
Mechanical advantage (MA) = Load (L)/Effort (E)
MA = L/E
Velocity ratio (VR) = Distance moved by load (l) / Distance moved by effort (e)
VR = l/e
Efficiency = work done by machine (Wd) /work put into the machine (Wp) x 100
Efficiency = Wd/Wp x100
Recall:
Work = Force x distance
Therefore,
Work done by machine (wd) = load (L) x distance (l)
Wd = L x l
Work put into the machine (Wp) = effort (E) x distance (e)
Wp = E x e
Note: the load and effort are measured in Newton (N), while the distance is measured in metre (m)
Efficiency = Wd/Wp x100
Efficiency = (L x l) / (E x e) x 100
Rearrange
Efficiency = L/E ÷ l/e x 100
But:
MA = L/E
VR = l/e
Therefore,
Efficiency = L/E ÷ l/e x 100
Efficiency = MA ÷ VR x 100
Efficiency = MA / VR x 100
