Answer: The person sitting in the middle of the train sees the back of the train enter ing the tunnel before the front end comes out.
Explanation:
Answer:
The Answer is D!
Explanation:
I checked it on Khan Academy.
Heat = change in internal energy + Work done The internal energy of a system = heat added and mechanical work done by the system, i.e. U = Q + W rearranging the formula above, will give us: Q = deltaU + W
Q = U - W = 604 kJ - 43.0 kJ = 561,000 J would be the answer.
Answer:
Explanation:
a) The magnitude of the net force on the student = 0 N since the student is standing still on level ground and upward reaction force = downward force.
b) the magnitude of the contact force on the student by the backpack = 80 N since the student was backing the backpack
c) the magnitude of the contact force o the student by the ground = 550 N + 80 N = 630 N reactional force on the student
