Answer:
4 seconds
Explanation:
Given:
v₀ = 0 m/s
v = 20 m/s
a = 5 m/s²
Find: t
v = at + v₀
20 m/s = (5 m/s²) t + 0 m/s
t = 4 s
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Answer:
Minimum uncertainty in velocity of a proton,
Explanation:
It is given that,
A proton is confined to a space 1 fm wide, 
We need to find the minimum uncertainty in its velocity. We know that the Heisenberg Uncertainty principle gives the uncertainty between position and the momentum such that,

Since, p = mv





So, the minimum uncertainty in its velocity is greater than
. Hence, this is the required solution.
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
Answer:
reviewing the statement we can say that it is FALSE
Explanation:
The Doppler effect is the change in the perceived frequency of a sound wave by the RELATIVE MOTION of the source and the observer.
This effect is very useful for finding the speed of an object.
When reviewing the statement we can say that it is FALSE