Answer:
56 kg
Explanation:
The change in potential energy of the man is given by:
where
m is the man's mass
g is the gravitational acceleration
is the change in height of the man
In this problem, we have:
is the gain in potential energy
g = 9.8 m/s^2 is the gravitational acceleration
is the change in height
Re-arranging the equation and substituting the numbers, we find the mass:
Answer:
If you add the 2 velocity vectors you get the velocity of the third vector which is the (change in) velocity of the cue ball after striking the cushion
V * 2 * cos 45 = 4 * cos 45 = 2.83 m/s
B) The heat absorbed by the engine is
while the heat expelled is
, therefore the work done by the engine is the difference between the heat absorbed and the heat expelled:
a) The efficiency of the engine is the ratio between the work done by the engine and the heat absorbed, therefore:
Answer:
Option E is the correct answer.
Explanation:
Velocity of boat = 10.8 m/s
Velocity of river = 2 m/s
Relative velocity upstream = 10.8 - 2 = 8.8 m/s
Displacement = Velocity x Time
1100 = 8.8 x t₁
Time in upstream, t₁ = 125 s
Relative velocity downstream = 10.8 + 2 = 12.8 m/s
Displacement = Velocity x Time
1100 = 12.8 x t₂
Time in downstream, t₂ = 86 s
Total time = t₁ + t₂ = 125 + 86 = 211 s
Option E is the correct answer.
