A descending elevator of mass 1,000 kg is uniformly decelerated to rest over a distance of 8 m by a cable in which the tension i
1 answer:
The speed of the elevator at the beginning of the 8 m descent is nearly 4 m/s. Hence, option A is the correct answer.
We are given that-
the mass of the elevator (m) = 1000 kg ;
the distance the elevator decelerated to be y = 8m ;
the tension is T = 11000 N;
let us determine the acceleration 'a' by using Newton's second law of motion.
∑Fy = ma
W - T = ma
(1000kg x 9.8 m/s² ) - 11000N = 1000 kg x a
9800 - 11000 = 1000
a = - 1.2 m/s²
Using the equation of kinematics to determine the initial velocity.
² =
² + 2ay
= √ ( 2 x 1.2m/s² x 8 m )
= √19.2 m²/s²
= 4.38 m/s ≈ 4 m/s
Hence, the initial velocity of the elevator is 4m/s.
Read more about the Equation of kinematics:
#SPJ4
You might be interested in
The resonant frequency of a RLC circuit in series is the frequency at which the inductive reactance and the capacitive reactance are equal:
where:
(1)
where
f is the frequency
L is the inductance
C is the capacitance
In our circuit, we have the inductance:
and the resonant frequency:
so we can re-arrange eq.(1) to find the capacitance of the circuit:
where:
where
f is the frequency
L is the inductance
C is the capacitance
In our circuit, we have the inductance:
and the resonant frequency:
so we can re-arrange eq.(1) to find the capacitance of the circuit:
To solve this problem we will use the concept related to nautical miles per hour (Knot) To miles per hour. From the definition we know that
So if the aircraft travels to 500 Knots we would have to
Therefore the speed in miles per hour is 575.39mph