Answer:
The time is
The speed is
Explanation:
From the question we are told that
The height of the cliff is
Generally from kinematic equation we have that
before the jump the persons initial velocity is u = 0 m/s
So
=>
Generally from kinematic equation
=>
=>
Answer:
400 J
Explanation:
The efficiency of a machine is defined as
where
is the work output
is the work input
For this machine, we know the following
is the work in input
is the efficiency
Solving for the work output, we find
Answer:
t₂> t₁
Explanation:
When the package reaches the braking ramp it gives a constant acceleration, which slows it down in distance d, let's use the kinematic equations to find this acceleration ration, when the package stops or speed is zero
v²= v₀₁² + 2 a₁ d
0 = v₀₁² + 2 a₁ d
a1 = v₀₁² / 2d
This constant acceleration since it depends on the characteristics of the braking section,
Let's look for the time it takes to stop
v = vo - a₁ t
t = v₀₁ / a₁
Now let's calculate the time for the second package
t₂ = v₀₂ / a₁ (1)
As the initial velocity in the second case is greater and the acceleration is constant, the time must increase
t₂> t₁
We can calculate this value, write the equation for the two cases
v² = v₀₁² + 2 a₁ d
v² = v₀₂² + 2 a₁ 2d
v₀₁² + 2 a₁ d = v₀₂² + 2 a₁ 2d
v₀₂² - v₀₁² = 2 a₁ (2d - d)
v₀₂² = v₀₁² + 2 a₁ d
We substitute in 1
t₂ =1 / a₁ RA (v₀₁² + 2 a₁ d)
t₂ = RA (v₀₁₂ / a₁² + 2d / a₁)
t₂ = Ra (t₁² + 2 d / a₁)
t₂> t₁
Answer: A
Explanation: We know that f=p*n
f=50*300=15000 Hz = 15kHz.
Have a great day! <3