Answer:
the net force is acting upon the object. The net force is the vector sum of all the forces that act upon an object. That is to say, the net force is the sum of all the forces, taking into account the fact that a force is a vector and two forces of equal magnitude. Hope this helps you.
O no,O no,O no actualy the point is that I don’t know the answer to the question
Answer:
a) The car was moving at a speed of
b) The negative sign of denotes that the observer is coming towards the police car which is the source of the sound.
c)
Explanation:
Given:
- original frequency of the source,
- speed of the source,
- velocity of the obstacle car be,
- speed of sound,
- observed frequency,
<u>Using the equation from the Doppler's effect:</u>
a)
The car was moving at a speed of
b)
The negative sign of denotes that the observer is coming towards the police car which is the source of the sound.
c)
Now when,
Then,
Using the Doppler's eq.:
Answer:
The rate of increase of the energy content of the room when all the eletrical devices are on is 1650 W.
Explanation:
From conservation of energy,
Rate of energy transfer () = Rate of change of energy within the room ().
As according to the problem no heat transfer occurs through the walls of the room we can assume that there is no energy transferred to the outside of the room, i.e., .
If all the electric devices are on inside the room, then the rate of increase of energy is equal to the power () consumed bt the electrical devices inside the room. Therefore we can write,
I have a hunch that you've got the <em>question</em> totally covered, and what you actually need is the <em>answer.</em>
- Kinetic energy = (1/2) (mass) (speed²)
Multiply each side by 2 : 2 x KE = (mass) ( speed²)
Divide each side by (mass): Speed² = 2 x KE / mass
Square root each side: <em>Speed = √(2 KE/mass)</em>
Look at that ! The question GIVES you the KE and the mass. All you have to do is plug those 2 numbers into the right side of that equation, turn the crank, do the arithmetic, and the speed falls out.
I get 200 m/s . You need to check my work.
(IF that's correct or anywhere close, it's equivalent to something around 447 miles per hour, which is very reasonable for a cruising airliner.)