It depends on how much time 45 j will go, so if you told me that it went through 45 j per minute it will go through for 2 minutes so not efficient unless it went through 45 j per hour then it is efficient.
I think the correct answer from the choices listed above is option D. One advantage of using electromagnets in devices would be that electromagnets can <span>easily be turned on and off. Hope this answers the question. Have a nice day.</span>
Black hole
hope it helped
Answer:
If we have large numbers (b is positive) or small numbers (b is negative), then this way ... 1, and V2i = 100 L, n2i = 5 + 2 + 1 = 8 in vessel 2. ... a good working substance in the barometer.
The total momentum of the system is preserved through the collision.
Note that momentum is
P = m*v
where m = mass
v = velocity.
Initial momentum:
P1 = (30000 kg)*(2 m/s) = 60000 (kg-m)/s for the moving car
P2 = 0 for the starionary car.
Final momentum:
P3 = (30000 + 30000)*v = 60000v (kg-m)/s
Because momentum is preserved,
P3 = P1 + P2
60000v = 60000
v = 1 m/s
The final velocity is 1 m/s.
Answer: 1.0 m/s