The half-life of Cs-137 is 30.2 years. If the initial mass of the sample is 1.00 kg, how much will remain after 151 years?

What instrument is used to expand burr holes?

k0ka [10]

Craniotomes are used

4 0

3 years ago

To develop muscle tone, a woman lifts a 2.50 kg weight held in her hand. She uses her biceps muscle to flex the lower arm throug

Romashka [77]

To solve this problem we will use the concepts related to Torque as a function of the Force in proportion to the radius to which it is applied. In turn, we will use the concepts of energy expressed as Work, and which is described as the Torque's rate of change in proportion to angular displacement:

$\tau = Fr$

Where,

F = Force

r = Radius

Replacing we have that,

$\tau = Fr$

$\tau = 21cm (\frac{1m}{100cm})* 550N$

$\tau = 11.55Nm$

The moment of inertia is given by 2.5kg of the weight in hand by the distance squared to the joint of the body of 24 cm, therefore

$I = 0.25Kg\cdot m^2 +(2.5kg)(0.24m)^2$

$I = 0.394kg\cdot m^2$

Finally, angular acceleration is a result of the expression of torque by inertia, therefore

$\tau = I\alpha \rightarrow \alpha = \frac{\tau}{I}$

$\alpha = \frac{11.55}{0.394}$

$\alpha = 29.3 rad/s^2$

PART B)

The work done is equivalent to the torque applied by the distance traveled by 60 °° in radians $(\pi / 3)$ , therefore

$W = \tau \theta$

$W = 11.5* \frac{\pi}{3}$

$W = 12.09J$

4 0

3 years ago

Warm water is generally less dense than cold water. The mass of a ship increases as it is loaded with cargo. If a ship will be s

KengaRu [80]

If a ship will be sailing through warm and cold water, people think about making it less dense than the warmest water as they load the ship with cargo. I think you forgot to give the options along with the question. I hope that this is the answer that has actually come to your desired help.

6 0

3 years ago

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A 2.74 g coin, which has zero potential energy at the surface, is dropped into a 12.2 m well. After the coin comes to a stop in

VikaD [51]

Answer:

B. - 0.328

Explanation

Potential Energy: This is the energy of a body due to position.

The S.I unit of potential energy is Joules (J).

It can be expressed mathematically as

Ep = mgh........................... Equation 1

Where Ep = potential energy, m = mass of the coin, h = height, g = acceleration due to gravity,

Given: m = 2.74 g = 0.00274 kg, h = 12.2 m, g = 9.8 m/s²

Substituting these values into equation 1

Ep = 0.00274×12.2×9.8

Ep = 0.328 J.

Note: Since the potential energy at the surface is zero, the potential Energy with respect to the surface = -0.328 J

The right option is B. - 0.328

7 0

3 years ago

What parts are found in an electric generator? Check all that apply.

Blizzard [7]

Answer:

an armature a permanent magnet brushes slip rings

Explanation:

6 0

3 years ago

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