Answer:
Explanation:
According to the work energy theorem, the work done by all the forces by a body is equal to the change in kinetic energy of the body.
Work done = change in kinetic energy
W = Final kinetic energy - initial kinetic energy
So, work causes change in kinetic energy.
Answer:
Explanation:
Wave length of sound from each of the speakers = 340 / 1700 = .2 m = 20 cm
Distance between first speaker and the given point = 4 m.
Distance between second speaker and the given sound
= √ 4² + 2² = √16 +4 = √20 = 4.472 m
Path difference = 4.472 - 4 = .4722 m.
Path difference / wave length = 0.4772 / 0.2 = 2.386
This is a fractional integer which is neither an odd nor an even multiple of half wavelength. Hence this point of neither a perfect constructive nor a perfect destructive interference.
B.
The child is too old to be gaining something from the screen time.
Answer:
0.106
Explanation:
For 1 liter of diesel the car can get 19 km, if it takes 0.2 MJ for each km then it would take the total energy of 19*0.2 = 3.8 MJ to move an aerodynamic car 19 km. Since 1 liter of of diesel also contains 36 MJ in internal energy, then the efficiency of the diesel engine is the ratio of its output energy over its input energy:
