The weight of a person increase when the elevator is going up.
<h3>
Weight of the person in the elevator</h3>
The weight of the person in the elevator is calculated as follows;
<h3>When the person is going up</h3>
F = ma + mg
F = m(a + g)
where;
- a is acceleration of the person
- g is acceleration due to gravity
<h3>When the person is going down</h3>
F = mg - ma
F = m(g - a)
Thus, the weight of a person increase when the elevator is going up.
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Answer:
v = 719.2 m / s and a = 83.33 m / s²
Explanation:
This is a rocket propulsion system where the system is made up of the rocket plus the ejected mass, where the final velocity is
v - v₀ =
ln (M₀ / M)
where v₀ is the initial velocity, v_{e} the velocity of the gases with respect to the rocket and M₀ and M the initial and final masses of the rocket
In this case, if fuel burns at 75 kg / s, we can calculate the fuel burned for the 10 s
m_fuel = 75 10
m_fuel = 750 kg
As the rocket initially had a mass of 3000 kg including 1000 kg of fuel, there are still 250 kg, so the mass of the rocket minus the fuel burned is
M = 3000 -750 = 2250 kg
let's calculate
v - 0 = 2500 ln (3000/2250)
v = 719.2 m / s
To calculate the acceleration, let's use the concept of the rocket thrust, which is the force of the gases on it. In the case of the rocket, it is
Push = v_{e} dM / dt
let's calculate
Push = 2500 75
Push = 187500 N
If we use Newton's second law
F = m a
a = F / m
let's calculate
a = 187500/2250
a = 83.33 m / s²
Equation: Mass x Velocity = Momentum
Answer: 93 x 13 = 1,209
Answer:
Δu=1300kJ/kg
Explanation:
Energy at the initial state

Is saturated vapor at initial pressure we have

Process 2-3 is a constant volume process

The overall in internal energy
Δu=u₁-u₃
We replace the values in equation
Δu=u₁-u₃

Δu=1300kJ/kg
Answer:
Maximum height reached by the rocket is

total time of the motion of rocket is given as

Explanation:
Initial speed of the rocket is given as

acceleration of the rocket is given as

engine stops at height h = 150 m
so the final speed of the rocket at this height is given as



so maximum height reached by the rocket is given as the height where its final speed becomes zero
so we will have



Now the total time of the motion of rocket is given as
1) time to reach the height of 150 m



2) time to reach ground from this height



so total time of the motion of rocket is given as
