Answer:
-0.55m/s
Explanation:
Given that: For the boy
Weight = 745N
Velocity = +0.35 m/s
Mass of the boy = ?
g = 9.81m/s^2
W = mg
745 = m×9.81
m = 75.94kg
For the girl
Given that:
Weight = 477 N
g = 9.81m/s^2
m = ?
W = mg
477 = m×9.81m/s^2
m = 48.62kg
To solve for the v of the girl, the two has to add up
48.62kg×v + 75.94kg×+0.35 m/s = 0
48.62v + 26.579 = 0
48.62v = - 26.579
v = -26.579/48.62
v = -0.5466
v = -0.55m/s
Hence, the velocity of the girl is -0.55m/s.
The negative sign is as a result of the two of them moving is opposite direction.
Answer:

Explanation:
The interaction of the piece of copper and water means that the first one need to transfer heat in order to reach a thermal equilibrium with water. Then:

After a quick substitution, the expanded expression is:



The final temperature of the system is:

Answer:
1. Just because it is small doesn't mean it needs to be excluded. If that were the case I would've been out of my friend group a while ago
2. Look at it it's fricking beautiful (see attachment)
3. It is just a great planet I don't think there needs to be any reason given I meannn you agree?
4. There's no other reason needed it's fricking gorgeous and amazing it needs no other reason. It needs a freaking
opening announcement to announce the arrival of the gorgeouness.
Answer:
3.6 KJ
Explanation: Given that a 70-kg boy is surfing and catches a wave which gives him an initial speed of 1.6 m/s. He then drops through a height of 1.60 m, and ends with a speed of 8.5 m/s. How much nonconservative work (in kJ) was done on the boy
The workdone = the energy.
There are two different energies in the scenario - the potential energy (P.E ) and the kinetic energy ( K.E )
P.E = mgh
P.E = 70 × 9.8 × 1.6
P.E = 1097.6 J
P.E = 1.098 KJ
K.E = 1/2mv^2
K.E = 1/2 × 70 × 8.5^2
K.E = 2528.75 J
K.E = 2.529 KJ
The non conservative workdone = K.E + P.E
Work done = 1.098 + 2.529
Work done = 3.63 KJ
Therefore, the non conservative workdone is 3.6 KJ approximately
Answer:
7.0 s, 69 m/s
Explanation:
If we take down to be positive, then the time to reach the ground is:
x = x₀ + v₀ t + ½ at²
240 m = (0 m) + (0 m/s) t + ½ (9.8 m/s²) t²
t = 7.0 seconds
The final velocity is:
v² = v₀² + 2a(x - x₀)
v² = (0 m/s)² + 2(9.8 m/s²) (240 m - 0 m)
v = 69 m/s