This is not as simple as it looks.
His average speed is NOT (10km/hr + 50km/hr)/2 = 30 km/hr.
You have to use the definition of speed:
Speed = (total distance covered) / (time to cover the distance).
Let's say the distance up (and down) the hill is 'd' .
Then the time it takes to go up the hill is (d/10) hours.
And the time it takes to come down the hill is (d/50) hours.
Total distance = 2d km
Total time = (d/10) + (d/50) = (5d/50) + (d/50) = 6d/50
Speed = distance/time = 2d/(6d/50) = 100d/6d
<em>Speed = </em>100/6 = <em>16-2/3 km/hr</em>
Question: How fast was the arrow moving before it joined the block?
Answer:
The arrow was moving at 15.9 m/s.
Explanation:
The law of conservation of energy says that the kinetic energy of the arrow must be converted into the potential energy of the block and arrow after it they join:
where is the mass of the arrow, is the mass of the block, of the change in height of the block after the collision, and is the velocity of the arrow before it hit the block.
Solving for the velocity , we get:
and we put in the numerical values
,
and simplify to get:
The arrow was moving at 15.9 m/s
Answer:
hey answer in the comment section
Answer:
Secondary structure
The secondary structure arises from the hydrogen bonds formed between atoms of the polypeptide backbone. The hydrogen bonds form between the partially negative oxygen atom and the partially positive nitrogen atom