Which of the following distances is the longest?a. 0.006 kilometers

A 740-kg boulder is raised from a quarry 119 m deep by a long uniform chain having a mass of 550 kg . This chain is of uniform s

Naddika [18.5K]

Answer:

A) the maximum acceleration the boulder can have and still get out of the quarry

B) how long does it take to be lifted out at maximum acceleration if it started from rest

Explanation:

A)

let +y is upward. look below at the free body diagram. the mass M refers to the combined mass of the boulder and chain.

the weight of the chain is: $w_{c} =m_{c} g$ and maximum tension is $T=2.50 m_{c} g=1.41*10^4N$

total mass and weight is :

$M =m_{c}+ m_{b} =740kg+550kg=1290 kg$

$w_{M} =1.2650*10^4N$

∑ $F_{y} =ma_{y}$

$T-M_{g} =Ma_{y}$

$a_{y} =(t-M_{g} )/M=(2.50m_{c} -M_{g} )/M=(2.50.550kg-1290kg)(9.8m/s^2)/1290kg$

$=0.645m/s^2$

B)

maximum acceleration

$a_{y} =0.645m/s^2\\\\y-y_{0} =119m\\v_{0y} =0$

using $y-y_{0} =v_{oy} t+1/2(a_{y} )t^2$

to solve for t

$t=\sqrt{2(y-y_{0} )/a_{y} }$

$t=\sqrt{2(119m)/0.645m/s^2} =19.20s$

6 0

3 years ago

Name three ways that being obese puts a strain on your heart & can lead to serious health problems.

Wittaler [7]

Answer:

Obesity changes in the structure and function of the heart. It increases your risk of heart disease. The more you weigh, the more blood you have flowing through your body. The heart has to work harder to pump the extra blood.

Explanation:

3 0

2 years ago

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a motorcycle starts from rest covers 200 meter distance in 6 second calculate final velocity and acceleration

Ivanshal [37]

Explanation:

s = ut + 1/2 a t^2

200 = 0 * 6 + 1/2 * a * (6)^2

200 = 1/2 * a * 36

200 = 18 a

a = 200/18

a= 11.1m/sec^2

v = u + at

v = 0 + 11.1 * 6

v = 66.6m/s

hope it helps you

3 0

2 years ago

Heartburn is a form of indigestion felt as a burning sensation in the chest when stomach acid comes back up into the esophagus.

xenn [34]

The antacid is basic so it neutralizes acidity or lowers it. Then if it goes into the esophagus, it's not as strong and it doesn't hurt, and it also calms your stomach because the acidity in your stomach is also lower. Antacids are therefore taken by many people, especially as they grow older and things like heartburn become more common.

5 0

2 years ago

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Why it is important to have exact standards of measurement

Tamiku [17]

Answer:

reference against doubt

Explanation:

exact standards of measurement are a reference point for situations in doubt , a line against which to test and observe.

6 0

3 years ago