What kind of mirrors are typically used for security purposes?

The length of a rectangular sheet of metal decreases by 34.5 cm. Its width decreases proportionally. If the sheets original widt

devlian [24]

The original width was 94.71 cm
The area decreased 33.1% 

The equation for the final size is 
2X^2 = 1.2 m^2 
X^2 - 0.6 m^2 
X^2 = 10000 * .6 cm 
X = 77.46 cm (this is the width) 

The length is 2 * 77.46 = 154.92 cm 

The original length was 154.92 + 34.5 = 189.42 cm 
The original width was 189.42 / 2 = 94.71 cm 

The original area was 94.71 * 189.92 = 17939.9 cm^2 
The new area is 79.46 * 154.92 = 12000.1 cm^2 

The difference between the original and current area is 17939.9 - 12000.1 = 5939.86 cm^2 

The percentage the area decreased is 5939.86 ' 17939.9 = 33.1%

6 0

3 years ago

The collision between a hammer and a nail can be considered to be approximately elastic. estimate the kinetic energy acquired by

Setler [38]

Here we can use momentum conservation as in this type of collision there is no external force on it

$m_1v_{1i} + m_2v_{2i} = m_1 v_{1f} + m_2v_{2f}$

now here we can say

$m_1 = 10 g$

$v_{1i} = 0$

$m_2 = 550 g$

$v_{2i} = 3.5 m/s$

now here we can say

$10*0 + 550 * 3.5 = 10 v_{1f} + 550 v_{2f}$

$192.5 = v_{1f} + 55 v_{2f}$

now by coefficient of restitution

for elastic collision we know that e = 1

$v_{2f} - v_{1f} = e(v_{1i} - v_{2i})$

$v_{2f} - v_{1f} = 0 - 3.5$

now by solving the two equation

$56v_{2f} = 189$

$v_{2f} = 3.375 m/s$

also we know that

$v_{1f} = v_{2f} + 3.5 = 3.375 + 3.5 = 6.875 m/s$

so final speed of the nail is 6.875 m/s

6 0

2 years ago

Read 2 more answers

Consider a river flowing toward a lake at an average speed of 3 m/s at a rate of 550 m3/s at a location 58 m above the lake surf

Vladimir [108]

Answer:

1. 0.574 kJ/kg

2. 315.7 MW

Explanation:

1. The mechanical energy per unit mass of the river is given by:

$E_{m} = E_{k} + E_{p}$

$E_{m} = \frac{1}{2}v^{2} + gh$

Where:

Ek is the kinetic energy

Ep is the potential energy

v is the speed of the river = 3 m/s

g is the gravity = 9.81 m/s²

h is the height = 58 m

$E_{m} = \frac{1}{2}(3 m/s)^{2} + 9.81 m/s^{2}*58 m = 0.574 kJ/Kg$

Hence, the total mechanical energy of the river is 0.574 kJ/kg.

2. The power generation potential on the river is:

$P = m(t)E_{m} = \rho*V(t)*E_{m} = 1000 kg/m^{3}*550 m^{3}/s*0.574 kJ/kg = 315.7 MW$

Therefore, the power generation potential of the entire river is 315.7 MW.

I hope it helps you!

4 0

2 years ago

A barrel of oil is exactly 42 gal. how many liters of oil are in a barrel

Natali [406]

The conversion from gallons to liters is 1 = 3.785.

Keeping this in mind...

42 x 3.785 = 158.97 liters.

If rounding, there are about 159 liters of oil in a barrel.

6 0

2 years ago

Predict what happens when glucose levels are high in the humms body

Goryan [66]

Glucose is blood sugar (hyperglycemia) comes from diabeties often, but can occur with other reasons, when glucose is to high someoenes sugar raises. Often this can lead to a diabetic coma, fatigue, vomiting, hospitalization, and even death if serious enough, from to high sugar. Many things can happen after this, and a lot are serious.

on the flip side (hypoglycemia) if sugar gets to low, confusion, fainting, vomiting, and nausea occur, as well as comas, and death if serious enought.

5 0

3 years ago