Answer:
F = 2389.603 N
Explanation:
Given:
Mass m = 1,369.4 kg
Initial velocity u = 28.9 m/s
Final velocity v = 20 m/s
Time t = 5.1 s
Find:
Net force
Computation:
a = (v - u)/t
a = (20 - 28.9)/5.1
a = -1.745 m/s²
F = ma
F = (1369.4)(1.745)
F = 2389.603 N
Complete Question
A certain refrigerator, operating between temperatures of -8.00°C and +23.2°C, can be approximated as a Carnot refrigerator.
What is the refrigerator's coefficient of performance? COP
(b) What If? What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump? COP
Answer:
a

b
Explanation:
From the question we are told that
The lower operation temperature of refrigerator is
The upper operation temperature of the refrigerator is 
Generally the refrigerators coefficient of performance is mathematically represented as

=> 
=> 
Generally if a refrigerator (operating between the same temperatures) was instead used as a heat pump , the coefficient of performance is mathematically represented as
=>
=>
Gravity obeys the inverse square law. At 6400 km above the center of the Earth (Earth's surface) you weigh x. Twice that reduces your weight to 1/4th. Four times that height reduces your weight to 1/16th. 4 times 6400 km is 25,600 km. But that is above the center of the earth, and the question requests the height above the surface, so we deduct 6400 km to arrive at our final answer: 19,200 km.
Incidentally, it doesn't exactly work the opposite way. At the center of the Earth the mass would be equally distributed around you, and you would therefore be weightless.
Answer:
236.3 x
C
Explanation:
Given:
B(0)=1.60T and B(t)=-1.60T
No. of turns 'N' =100
cross-sectional area 'A'= 1.2 x
m²
Resistance 'R'= 1.3Ω
According to Faraday's law, the induced emf is given by,
ℰ=-NdΦ/dt
The current given by resistance and induced emf as
I = ℰ/R
I= -NdΦ/dtR
By converting the current to differential form(the time derivative of charge), we get
= -NdΦ/dtR
dq= -N dΦ/R
The change in the flux dФ =Ф(t)-Ф(0)
therefore, dq =
(Ф(0)-Ф(t))
Also, flux is equal to the magnetic field multiplied with the area of the coil
dq = NA(B(0)-B(t))/R
dq= (100)(1.2 x
)(1.6+1.6)/1.3
dq= 236.3 x
C
Answer: Yes, he is exceeding the speed limit
Explanation:
Hi!
This is problem about unit conversion
1 mile = 1,609.344 m
Then the speed limit v is:
v = 75 mi/h = 120,700.8 m/h
1 hour = 60 min = 60*60 s = 3,600 s
v = (120,700.8/3,600) m/s = 33.52 m/s
38 m/s is higher than the speed limit v.