Answer: the answer is 7
Step-by-step explanation: add 9 to both sides, eliminating -9 so now you have 7x=49 divide both by 7 and you get x= 7 check it by inputing 7 for x, 7(7)-9=40
7(7)=49 next 49-9= 40
it checks out, so x= 7
Answer:
12 * 50 = 600
Step-by-step explanation:
We have to multiply 12 by 50
<u>Short cut method for multiplying a number by 50</u>
Step 1: Take the half of the given number
Step 2: Multiply the result by 100
<u>To find the short cut method to multiply 12 by 50</u>
Here the number is 12
Step 1: divide the number by 2
12/2 = 6
Step 2: Multiply 6 by 100 we get 600
Therefore 12 * 50 = 600
Answer:A
Step-by-step explanation:
<span>Acceleration of a passenger is centripetal acceleration, since the Ferris wheel is assumed at uniform speed:
a = omega^2*r
omega and r in terms of given data:
omega = 2*Pi/T
r = d/2
Thus:
a = 2*Pi^2*d/T^2
What forces cause this acceleration for the passenger, at either top or bottom?
At top (acceleration is downward):
Weight (m*g): downward
Normal force (Ntop): upward
Thus Newton's 2nd law reads:
m*g - Ntop = m*a
At top (acceleration is upward):
Weight (m*g): downward
Normal force (Nbottom): upward
Thus Newton's 2nd law reads:
Nbottom - m*g = m*a
Solve for normal forces in both cases. Normal force is apparent weight, the weight that the passenger thinks is her weight when measuring by any method in the gondola reference frame:
Ntop = m*(g - a)
Nbottom = m*(g + a)
Substitute a:
Ntop = m*(g - 2*Pi^2*d/T^2)
Nbottom = m*(g + 2*Pi^2*d/T^2)
We are interested in the ratio of weight (gondola reference frame weight to weight when on the ground):
Ntop/(m*g) = m*(g - 2*Pi^2*d/T^2)/(m*g)
Nbottom/(m*g) = m*(g + 2*Pi^2*d/T^2)/(m*g)
Simplify:
Ntop/(m*g) = 1 - 2*Pi^2*d/(g*T^2)
Nbottom/(m*g) = 1 + 2*Pi^2*d/(g*T^2)
Data:
d:=22 m; T:=12.5 sec; g:=9.8 N/kg;
Results:
Ntop/(m*g) = 71.64%...she feels "light"
Nbottom/(m*g) = 128.4%...she feels "heavy"</span>
