Answer:
heat is the transfer of thermal energy from a system to its surroundings or from ... It is very important to know that, in science, heat and temperature are not the same thing. ... Have you noticed that when you put a cold, metal teaspoon into your hot cup of ... AIM: To investigate which materials are the best conductors of heat.
Explanation:
Answer:
6.13428 rev/s
Explanation:
= Final moment of inertia = 4.2 kgm²
I = Moment of inertia with fists close to chest = 5.7 kgm²
= Initial angular speed = 3 rev/s
= Final angular speed
r = Radius = 76 cm
m = Mass = 2.5 kg
Moment of inertia of the skater is given by

In this system the angular momentum is conserved

The rotational speed will be 6.13428 rev/s
Answer:
<em>1. c. Same in both</em>
<em>2. a. Case 1</em>
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Explanation:
1. The balls are identical in all sense, which means that if they are dropped from the same height, they should posses the same kinetic energy just before they collide with either the concrete floor or the stretchy rubber. Also, since they reach the same height when they bounced of the concrete floor or the piece of stretchy rubber, it means that they posses the same amount of kinetic energy at this point. Since their kinetic energy at these two points are the same, and they have the same masses, then this means that their momenta at these two instances will also be equal. Since all these is true, then the change in the momentum of the balls between the instance just before hitting the concrete floor or the stretchy rubber material and the instant the ball just leave the floor or the stretchy material is the same for both.
2. The ball that falls on the concrete will experience the greatest force, since the time of impact is small, when compared to the time spent by the other ball in contact with the stretchy rubber material; which will stretch, thereby extending the time spent in contact between them.
You haven't told us the "wattage" rating of the bulb. We'll just have to call it ' W ' .
The bulb uses energy at the rate of W watts, or 0.001W kilowatts.
In 12 hours, it uses <em>0.012W kilowatt-hours </em>of energy.
= = = = =
W watts = W Joules/second
1 hour = 3600 seconds
12 hours = (12 x 3600) seconds
Energy = (W Joule/sec) x (12 x 3600 sec)
<em>Energy = 43,200W Joules</em>