Answer:
all of the above
Explanation:
- a build up of electric charge
- the force and motion of electrically charged particles
- an electric current
are three different ways to describe electricity.
So the answer is all of the above.
Answer:
Answer D: It describes the relationship between motion and force.
Explanation:
The answer is D because a law is something that describes something in nature, but does not try to explain how or why is occurs (that is a theory). Options B and C sound more like theories, while option A sounds like a definition. Option D is correct because a law describes without explaining.
Answer:
2. ( b ) zero
3. ( c ) 10 s
4. Uniform then decreasing
Explanation:
2.
Since the motion is uniform, initial and final velocity will be 0, hence acceleration will be zero.
3.
Initial velocity ( u ) = 5 m/s
Final velocity ( v ) = 35 m/s
Acceleration ( a ) 3 m/s^2
To find : Time ( t )
Formula : -
t = v - u / a
= 35 - 5 / 3
= 30 / 3
t = 10 s
Answer:

Explanation:
Given:
mass of ice melted, 
time taken by the ice to melt, 
latent heat of the ice, 
Now the heat rejected by the Carnot engine:



Since we have boiling water as hot reservoir so:

The cold reservoir is ice, so:

Now the efficiency:



Now form the law of energy conservation:
Heat supplied:

where:
heat supplied to the engine




Now the work done:



For the answer to the question above, each horse's force forms a right angle triangle with the barge and subtends an angle of 60/2 = 30°. The resultant in the direction of the barge's motion is:
Fx = Fcos(∅)
We can multiply this by 2 to find the resultant of both horses.
Fx = 2Fcos(∅)
Fx = 2 x 720cos(30)
Fx = 1247 N