Answer:
<em>4.52secs</em>
Step-by-step explanation:
Given the height of a falling object expressed as;
d=3t+5t^2
If the object travel 84 feet, we are to find the time t it takes to travel. On substituting;
84 = 3t+5t^2
3t+5t^2 - 84 = 0
t = -5±√25-4(3)(-84)/2(3)
t = -5±√25+1008/6
t = -5±32.14/6
t = -5+32.14/6
t = 27.14/6
<em>t = 4.52 secs</em>
<em>Hence it will take 4.52secs for the object to travel 84feet</em>
Answer:
261 km
Step-by-step explanation:
given,s=constant
d1/T1=d2/T2
d1=90km,t1=50 min
d2=? ,t2=(120+25)min
=145min
therefore,d2=(90×145)/50
=261 km
Answer: Aproximately 2,525 balloons
Step-by-step explanation:
1. Find the volume of a balloon with the formula given in the problem, where
is the radius (
), then:

2. Convert the volume from m³ to lliters by multiplying it by 1,000:

3. You know that that 1 liter of helium can lift 1 gram and that Ryan weighs 5 stone and 5 pounds. So you must make the following conversions:
1 g=0.0022 lb
From 5 stones to pounds

4. Then Ryan's weigh is:
5lb+70lb=75lb
5. Then, if 1 liter of helium can lift 0.0022 lb, to lift 75 lb (which is the weight of Ryan) they need:

6. Then, to calculate the aproximated number of balloons they need to make him float (which can call
), you must divide the liters of helium needed to lift the weight of Ryan by the volume of a balloon, then the result is:

≈2,525 balloons.
Answer:
18 acres
Step-by-step explanation:
: ) hope it helps......
Answer:
Cone.
Step-by-step explanation:
From the given figure it is clear the hat is look like a solid figure, which have a circular base and single vertex, i.e., cone.
The following attributes help as to decide that the hat is a cone:
1. Hat and cone both have one vertex.
2. Hat and cone both have one circular base.
Therefore, the hat is look like cone.