Answer:
6.46
Step-by-step explanation:
h(t) = (1/2)
+ v0t + h0
Origin is at surface of water (h = 0), up is positive.
a = -g = -9.8 m/
v0 = 25 m/s
h0 = 50 m
h(t) = -4.9t2 + 25t + 50
Find t when
7 =
+ 25t + 50
- 25t - 43 = 0
t = [1/(2*4.9)] [25 ±√(
+ 4*4.9*43)]
t = (0.102)(25 ± 38.312)
t > 0 ⇒ use only the positive square root
t = (0.102)(25 + 38.312) ≅ 6.46 s
It is 7m above the water at about 6.46 s
Set it up as a proportion problem. $2.10 is to x pounds as $3.50 is to 1 pound
=$2.10/x pounds= $3.50/1 pound
Cross multiply
=($2.10 * 1)=($3.50 * x)
=2.10=3.50x
Divide both sides by 3.50
0.6= x
x= 0.6=6/10= 3/5
He can purchase 0.6 (or 3/5 in fraction terms) pounds for $2.10.
Hope this helps! :)
Answer:
$55
Step-by-step explanation:
Let b represent the original bill. The problem statement tells us ...
20% × (b -6) = 9.80
Dividing by 20% gives ...
b -6 = 49.00
b = 55.00 . . . . . . . add 6
Their bill before the discount was $55.00.
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<em>Comment on the tip</em>
It is generally considered better form to tip on the basis of the original bill before coupons and discounts.