Hi my friend, since momentum is always conserved without external forces, the momentum after the collosion will still be 0.06 kg*m/s. Hope it helps☺
The figure shows the arrangement of system
The velocity of boat can be resolved in to two
Horizontal component = vcos θ = 2.50 cos 45 = 1.768 m/s
Vertical component = vsin θ = 2.50 sin 45 = 1.768 m/s
Due to horizontal component the boat arrive arrives upstream,
Total horizontal velocity = 1.768 - Vr, where Vr is the velocity of river.
Total time taken to cross the river = width of river/ Vertical component of velocity
t = 285/1.768 = 161.20 seconds
So 118 meter is traveled at a velocity of 1.768-Vr in 161.20 seconds
That is 118 = (1.768-Vr)*161.20
1.768 - Vr =0.732
Vr = 1.036 m/s
So velocity of river flow =1.036 m/s
Answer:
615 J
Explanation:
internal energy (U) = 504 J
heat lost (q) = 111 J = - 111 J (negative sign is because heat is lost)
work done = 222 J
what is the final energy in the system
total energy = final energy - initial energy
final energy = total energy + initial energy
where
initial energy = 504 J
total energy = 222 - 111 = 111 J
final energy = 504 + 111 = 615 J
That is because there are other forces like the friction forces that apply differently on both of them. The frictional forces applied to the sled are smaller than they are on the father, for example, so it's possible for him to pull it.