Answer:
(a) 300 W
(b)0.90 J
Explanation:
(a) The electric power for any circuit element is given as
Here I is current passing in the circuit and V is the voltage.
Given I = 12 A and V =25 V.
Substitute the given values, we get
P = 300 W.
Thus, the power defibrillator deliver to the body is 300 W.
(b) To calculate the electric energy use the relation between electric energy, power and time as
Given t = 3 ms.
Substitute the values, we get
E = 0.90 J.
Thus, the energy transferred is 0.90 J.
The correct options are:
<span>B. Radiation is heat flowing in waves.
C. Conduction is heat flowing between two objects that are touching each other.
In fact, radiation is heat transferred by electromagnetic waves, while conduction is the heat transfer between touching objects (the particles of one object collide with the particle of the other object, and so heat is transferred via the transfer of kinetic energy between the molecules).
Instead, option A is wrong (because conduction </span>is the heat transfer between touching objects) and option D is wrong because convection is the heat flowing when a liquid or a gas carries the heat.
The answer is refraction. When a wave from one medium enters another medium, its direction changes due to the change of speed (phase velocity changes but frequency remains the same). The wave slows down when it enters a denser medium from the one it came from hence its path seems to bend.
Answer:
2 a) it is less dense than the water
2 b) it is more dense than the water
3 a ping pong ball is hollow and less dense than the water so it quickly bounces up to the surface of the water
Answer:
d.20760 J
Explanation:
We are given that
Mass of cart=m=100 kg
At the top,h=22 m
Amount of energy convert into heat due to friction=E=800 J
We have to find the kinetic energy at the bottom of the ramp.
Potential energy drop=mgh=
Kinetic energy at the bottom=Potential energy drop-energy lost due to friction
Kinetic energy at the bottom =(21560-800) J
Kinetic energy at the bottom=20760 J
Hence, the kinetic energy at the bottom of the ramp=20760 J
d.20760 J