Answer:
A) 89.39 J
B) 30.39J
C) 23.8 J
Explanation:
We are given;
F = 30.2N
m = 3.5 kg
μ_k = 0.646
d = 2.96m
ΔEth (Block) = 35.2J
A) Work done by the applied force on the block-floor system is given as;
W = F•d
Thus, W = 30.2 x 2.96 = 89.39 J
B) Total thermal energy dissipated by the whole system which includes the floor and the block is given as;
ΔEth = μ_k•mgd
Thus, ΔEth = 0.646 x 3.5 x 9.8 x 2.96 = 65.59J
Now, we are given the thermal energy of the block which is ΔEth (Block) = 35.2J.
Thus,
ΔEth = ΔEth (Block) + ΔEth (floor)
Thus,
ΔEth (floor) = ΔEth - ΔEth (Block)
ΔEth (floor) = 65.59J - 35.2J = 30.39J
C) The total work done is considered as the sum of the thermal energy dissipated as heat and the kinetic energy of the block. Thus;
W = K + ΔEth
Therefore;
K = W - ΔEth
K = 89.39 - 65.59 = 23.8J
B) Not work since decrease in temperature wouldnt cause evaporation or reverse in cycle.
Either A or D. If I were answering I'd go with my git answer and say A
Answer:
according to the new geometry lesson alcometry which will after 11 years in geometry
Total distance = 10 km + 10 km = 20 km
1 km = 1000 m
20km x 1000 = 20,000 m
Total time = 20 min. + 30 min. = 50 minutes
Average speed = Distance / time
Average speed = 20,000/50 min
Average speed = 400 m/s
