Answer:
Explanation:
Total Stopping distance is the sum of the reaction distance and the braking distance, such that ;
d=dr + db =1.47St +[ ( Si 2- Sf2 ) / 30(F/0.01G) ]
In this case, the reaction time, t, is the AASHTO standard, or 2. 5 s. The friction factor, F, is based upon the standard AASHTO deceleration rate of 11.2 ft/s2 (F = 11.2/32.2 = 0.348) and the speed is given as 40 mph.
d = 1.47x60x2.5+ [ (60^2-40^2) / 30x 0.348 ]
d = 220.5 + ( (3600-1600) / 10.44 )
d = 220.5 + 191.57
d = 412.07ft.
Since the sign can be seen clearly at 120 ft.
Then the position of the sign should be,
= 412.07 - 120
= 292.07 ft
Answer:
a)
, b)
, c) Irreversible.
Explanation:
a) The power input required by the refrigerator is:



b) The Coefficient of Performance of the refrigerator is:



c) The maximum ideal Coefficient of Performance of the refrigeration is given by the inverse Carnot's Cycle:



The refrigeration cycle is irreversible, as
.
we have
x<5
x>c
we know that
The solution is the intersection of both solution sets of the given inequalities.
The solutions of the compound inequality must be solutions of both inequalities.
The value of c could be 5 or any number greater than 5, such that there are no solutions to the compound inequality
Because
A number cannot be both less than 5 and greater than 5 at the same time
therefore
the answer is
for c_> there are no solutions to the compound inequality
Answer:
a) P ≥ 22.164 Kips
b) Q = 5.4 Kips
Explanation:
GIven
W = 18 Kips
μ₁ = 0.30
μ₂ = 0.60
a) P = ?
We get F₁ and F₂ as follows:
F₁ = μ₁*W = 0.30*18 Kips = 5.4 Kips
F₂ = μ₂*Nef = 0.6*Nef
Then, we apply
∑Fy = 0 (+↑)
Nef*Cos 12º - F₂*Sin 12º = W
⇒ Nef*Cos 12º - (0.6*Nef)*Sin 12º = 18
⇒ Nef = 21.09 Kips
Wedge moves if
P ≥ F₁ + F₂*Cos 12º + Nef*Sin 12º
⇒ P ≥ 5.4 Kips + 0.6*21.09 Kips*Cos 12º + 21.09 Kips*Sin 12º
⇒ P ≥ 22.164 Kips
b) For the static equilibrium of base plate
Q = F₁ = 5.4 Kips
We can see the pic shown in order to understand the question.
Answer:
S = 0.5 km
velocity of motorist = 42.857 km/h
Explanation:
given data
speed = 70 km/h
accelerates uniformly = 90 km/h
time = 8 s
overtakes motorist = 42 s
solution
we know initial velocity u1 of police = 0
final velocity u2 = 90 km/h = 25 mps
we apply here equation of motion
u2 = u1 + at
so acceleration a will be
a =
a = 3.125 m/s²
so
distance will be
S1 = 0.5 × a × t²
S1 = 100 m = 0.1 km
and
S2 = u2 × t
S2 = 25 × 16
S2 = 400 m = 0.4 km
so total distance travel by police
S = S1 + S2
S = 0.1 + 0.4
S = 0.5 km
and
when motorist travel with uniform velocity
than total time = 42 s
so velocity of motorist will be
velocity of motorist = 
velocity of motorist =
velocity of motorist = 42.857 km/h