1. white
2. colors
3. reflecting
4. light
5. waves interferences
6. reflect
7. add
8. brighter
9. cancel
Answer:
The net change in the internal energy of the gas in the piston is -343J
Explanation:
Because heat and workdone are the only means of energy transfer between the system and the surrounding, change in internal energy is given by;
∆E = q + w
q = heat transfer
w = workdone
Because heat is lost by the system, the heat transfer is negative
q = -413J
Because work is done on the system, workdone is positive
w = +70J
∆E = -413J + 70J
∆E = -343J
If the sign of work is negative, that means the force and the motion are in opposite directions.
Let's say you see something roll off of the shelf. You catch it, and you let it down slowly and gently.
Gravity exerted down-force on it and it moved down. Gravity did positive work on it.
YOU exerted UP-force on it and it moved down. YOU did negative work on it.
(Also, the falling object exerted down-force on your hand, and your hand moved down. The falling object did positive work on your hand ! Where did THAT energy come from ? It came from the potential energy that the object had while it was on the shelf. Your hand absorbed that energy on the way down, doing negative work. So the object didn't have any kinetic energy when it reached the floor, and it did NOT splinter the floor or shatter in smithereens. It had barely enough energy left to make a sound when it hit the floor.)
Answer:
4 seconds
Explanation:
bullet flies 200m/s. thus 800m/200m=4sec
Answer:
7.39 m/s
Explanation:
Applying
K.E = 1/2mv²..................... Equation 1
Where K.E = Kinetic Energy, m = mass of the ball, v = velocity of the ball.
Make v the subject of the equation
v = √(2K.E/m)................. Euqation 2
From the question,
Given: K.E = 30 J, m = 1.1kg
Substitute these values into equation 2
v = √(2×30/1.1)
v = √54.54
v = 7.39 m/s