Answer:
a)5.88J
b)-5.88J
c)0.78m
d)0.24m
Explanation:
a) W by the block on spring is given by
W= 
kx² = (530)(0.149)² = 5.88 J
b) Workdone by the spring = - Workdone by the block = -5.88J
c) Taking x = 0 at the contact point we have U top = U bottom
So, mg
= kx² - mgx
And, = ( kx² - mgx
)/(mg) = 
]/(0.645x9.8)
= 0.78m
d) Now, if the initial initial height of block is 3
= 3 x 0.78 = 2.34m
then, kx² - mgx - mg =0
(530)x² - [(0.645)(9.8)x] - [(0.645)(9.8)(2.34) = 0
265x² - 6.321x - 14.8 = 0
a=265
b=-6.321
c=-14.8
By using quadratic eq. formula, we'll have the roots
x= 0.24 or x=-0.225
Considering only positive root:
x= 0.24m (maximum compression of the spring)
Answer:
1,200 watts
Explanation:
1 watt = 1 Joule (J) of work / second
So, 3600 Joules of work / 3 seconds is:
3600 J / 3 seconds = 1,200 watts
Answer:
i. + 22.5 m ii. 4.0 m
Explanation:
i. Image distance
Using the lens formula
1/u + 1/v = 1/f where f = focal length = + 18.0 m, u = object distance = distance of shark away from lens = + 90.0 m and v = image distance from lens = unknown
So, we find v
1/v = 1/f - 1/u
= 1/+18 - 1/+90
= (5 - 1)/90
= 4/90
v = 90/4
= + 22.5 m
So the image is real and formed 22.5 m away on the other side of the lens.
ii Length of Shark
Using the magnification formula, m = image height/object height = image distance/object distance. image height = 1.0 m where object height = length of shark.
m = image distance/object distance
= v/u
= +22.5/+90
= 0.25
0.25 = image height/object height
So,
object height = image height/0.25
= 1.0 m/0.25
= 4.0 m
So, the length of the shark is 4.0 m
Answer:
The amount that is "vented" out by "the fans" is <u>$0.50</u> for 10 hours.
Option: a
<u>Explanation</u>:
"Energy discharged by air in every hour" can be determined by,
Q = heat energy (Joules, J)
m = mass of a substance (kg)
c = specific heat (units J/kg∙K)
∆T = 10 hours
Q = 576 × 1.00 × 10
Q = 5760 kJ/hours
W = 1.6 kwh
We know that, “Coefficient of performance” (COP)
Given that, COP = 3.2
W = 0.5 kwh
The unit cost of electricity is $0.10/kWh
The unit cost of electricity is $0.10/kWh
Unit electricity cost for 10 hours = 0.5 × 10 × 0.1$
Unit electricity cost for 10 hours = $0.5
The amount that is "vented out" by "the fans" is $0.50 for 10 hours.
