Step-by-step explanation:
First, we define the variables:
x: number of years after 1950
f (x): amount of vinyl sold.
Then, with the variables defined, we have:
68594 vinyl records were sold in 1958 ---------> f (8) = 68594
91299 vinyl records were sold in 1961 ---------> f (11) = 91299
38720 vinyl records were sold in 1952 ---------> f (2) = 38720
161743 vinyl records were sold in 1967 ---------> f (17) = 161743
Answer:
You aren't supposed to add 3k
Step-by-step explanation:
3k is a positve number. So instead of adding you have to subtract to be able to move on. Correct way shown below. Once you get this step wrong your answer will also be wrong. At the end you also need to divide
19-2k= 3k-1
-3k -3k
19-5k= -1
-19 -19
-5k= -20
-5/-5= -20/-5
k=4
Answer:
1 is 6
2 is 3.5
3 is 5
4 is 8.46
Step-by-step explanation:
if not sorry :-(
Answer:
a) W₁ = 78400 [J]
b)Wt = 82320 [J]
Step-by-step explanation:
a) W = ∫ f*dl general expression for work
If we have a chain with density of 10 Kg/m, distributed weight would be
9.8 m/s² * 10 kg = mg
Total length of th chain is 40 m, and the function of y at any time is
f(y) = (40 - y ) mg where ( 40 - y ) is te length of chain to be winded
At the beggining we have to wind 40 meters y = 0 at the end of the proccess y = 40 and there is nothing to wind then:
f(y) = mg* (40 - y )
W₁ = ∫f(y) * dy ⇒ W₁ = ∫₀⁴⁰ mg* (40 - y ) dy ⇒ W₁ = mg [ ∫₀⁴⁰ 40dy - ∫₀⁴⁰ ydy
W₁ = mg [ 40*y |₀⁴⁰ - 1/2 * y² |₀⁴⁰ ⇒ W₁ = mg* [ 40*40 - 1/2 (40)² ]
W₁ = mg * [1/2] W₁ = 10*9,8* ( 800 )
W₁ = 78400 [J]
b) Now we can calculate work to do if we have a 25 block and the chain is weightless
W₂ = ∫ mg* dy ⇒ W₂ = ∫₀⁴⁰ mg*dy ⇒ W₂ = mg y |₀⁴⁰
W₂ = mg* 40 = 10*9.8* 40
W₂ = 3920 [J]
Total work
Wt = W₁ + W₂ ⇒ Wt = 78400 + 3920
Wt = 82320 [J]
