Energy transfer in mechanical systems: During steady-state operation, a mechanical gearbox receives 70 KW of input power through
the input shaft and delivers power through the output shaft. Considering the gearbox as a thermodynamic system, the rate of convection heat transfer generated during its operation is defined by: where h 0.171 kW/m2-K is the convection heat transfer coefficient, A 1.0 m is the outer surface area of the gearbox, T 300 K is the temperature of the outer surface, and T 293 K is the temperature of the surrounding air. For the gearbox, evaluate the heat transfer rate, 2, and the power delivered through the output shaft, W.
1 answer:
You might be interested in
Answer:
51.4 Ohms
Explanation:
By applying voltage division rule
where v is voltage, subscripts i and f represnt initial and final, R is resistance, m is internal and l is external.Substituting 7V for final voltage, 10V for initial voltage and the external resistance as 120 Ohms then
Answer:
Bore = 7 cm
stroke = 6.36 cm
compression ratio = 10.007
Explanation:
Given data:
Cubic capacity of the engine, V = 245 cc
Clearance volume, v = 27.2 cc
over square-ratio = 1.1
thus,
D/L = 1.1
where,
D is the bore
L is the stroke
Now,
V =
or
V =
on substituting the values, we have
245 =
or
D = 7.00 cm
Now,
we have
D/L = 1.1
thus,
L = D/1.1
L = 7/1.1
or
L= 6.36 cm
Now,
the compression ratio is given as:
on substituting the values, we get
or
Compression ratio = 10.007
Answer:
t = 30.1 sec
Explanation:
If the ant is moving at a constant speed, the velocity vector will have the same magnitude at any point, and can be decomposed in two vectors, along directions perpendicular each other.
If we choose these directions coincident with the long edge of the paper, and the other perpendicular to it, the components of the velocity vector, along these axes, can be calculated as the projections of this vector along these axes.
We are only interested in the component of the velocity across the paper, that can be calculated as follows:
vₓ = v* sin θ, where v is the magnitude of the velocity, and θ the angle that forms v with the long edge.
We know that v= 1.3 cm/s, and θ = 61º, so we can find vₓ as follows:
vₓ = 1.3 cm/s * sin 61º = 1.3 cm/s * 0.875 = 1.14 cm/s
Applying the definition of average velocity, we can solve for t:
t = =
⇒ t = 30.1 sec