Answer:
1. The reason why nichrome wire is used in a heater is due to the properties of nichrome which makes it a material of choice for heating application including;
i) The cost of manufacture of nichrome is low
ii) Nichrome has both high mechanical and creep strength, and therefore is suitable for installation and use in a wide setting
iii) Nichrome has a high resistance to electron flow, making it a good electrical heating element
iv) Nichrome has a high resistance to oxidation, such that it can be reused several times as a heater
v) The high ductility of nichrome allows it to be stretched and drawn around different vessels with contents to which heat is to be supplied
2. Copper wire is not used in heaters because according to Joule's law, the heat produced from the flow of electric current, 'I', through a material having a resistance, 'R', for a time, 't', is proportional to I²·R·t, and copper has a very low resistance, 'R', to the flow of electric current, and therefore, will not produce sufficient heat required at a given current level
Explanation:
When waves travel across strings, the larger the tension of the string the faster the velocity of the wave. This is because of the equation:
v = the square root of (T/(m/L)) where T is the tension, m the mass of the string, and L the length of the string
Hope this helps!
Answer:
momentum= mass x velocity
= 11 x 1200 =13200kgm/s
Answer:
Use the drop-down menus to answer each question.
Which runner finished the 100 m race in the least amount of time?
✔ Ming
Which runner stopped running for a few seconds during the race?
✔ Chloe
At what distance did Anastasia overtake Chloe in the race?
✔ 40 m
Answer:
their momenta are opposite but equal
Explanation:
<em>Given are masses of a Russian cosmonaut and a USA astronaut in the sequence, </em>
<em>They are motionless initially and floating in the space without any friction.</em>
- When they face each other and push each other palm to palm they execute a perfectly elastic collision.
- Since the collision is perfectly elastic no part of the mechanical energy will convert into any other form of energy and the whole will contribute to the mechanical energy of the system.
- So according to the Newtons second law there will act an equal amount of force in opposite direction on both the bodies after they push each-other.
According to the law of conservation of linear momentum of this system the sum of initial momentum will be equal to the sum of final momentum of the bodies.
<u>Mathematically:</u>
∵since the bodies are initially at rest.
where the negative sign denotes the opposite direction.