True or False? To observe physical properties in matter, the matter must change into a new substance.

The half-life of a radioisotope is 6.0 hours. Approximately how long will it take for the activity of a sample to be reduced by

DerKrebs [107]

Answer:

1 hours will be the best answer

3 0

3 years ago

A satellite is orbiting the earth just above its surface. The centripetal force making the satellite follow a circular trajector

Pavlova-9 [17]

Answer:

$v=7905m/s$

$t=5063s$

Explanation:

A satellite is orbiting the earth just above its surface. The centripetal force making the satellite follow a circular trajectory is just its weight, so its centripetal acceleration is about 9.81 m/s2 (the acceleration due to gravity near the earth's surface). If the earth's radius is about 6370 km, how fast must the satellite be moving? How long will it take for the satellite to complete one trip around the earth?

The weight of the satellite is the centripetal force, so:

$W=mg=F_{cp}=ma_{cp}=m\frac{v^2}{r}$

Which means: $g=\frac{v^2}{r}$

We can calculate then the velocity:

$v=\sqrt{gr}=\sqrt{(9.81m/s^2)(6370000m)}=7905m/s$

For calculating how long will it take for the satellite to complete one trip around Earth we consider that the distance of the trip is the circumference of the orbit. This is calculated as $C=2\pi r$ .

Since velocity is v=d/t, we have:

$t=d/v=C/v=2\pi r/v=\frac{2\pi 6370000}{7905m/s} =5063s$

5 0

3 years ago

The Chartered Institute of Management Accountants defines activity-based cost management as follows: "An approach to the costing

egoroff_w [7]

Answer:

ABC is the activity based accounting. It is the costing done for each separate activity which maybe unit level, batch level, product sustaining or facility sustaining.

Explanation:

The basic difference between ABC and traditional costing systems can be explained with the help of the following diagram.

Traditional Costing System

Overhead Cost Accounts (For each individual expense e.g. tax)

First Stage Allocation

Cost Centers ( normally Departments)
Cost Centers ( normally Departments)

N. Cost Centers ( normally Departments)

Second Stage Allocation ( Direct Labor Or Machine Hours)

Cost Objects ( products, services and customers)

ACTIVITY BASED COSTING SYSTEMS

Overhead Cost Accounts (For each individual expense e.g. tax)

First Stage Allocation ( resource cost drivers)

Activity Cost Centers
Activity Cost Centers

N. Activity Cost Centers

Second Stage Allocation ( activity cost drivers)

Cost Objects ( products, services and customers) (Direct Costs)

Four steps are involved in the design of ABC systems.

identifying the major activities that take place in an organization
assigning cost to cost pools / cost centers for each activity
determining the cost for each major activity
assigning the cost of activities to products according to the product's demand for activities.

The first two steps relate to the first stage and final two steps to the second stage of the two - stage allocation process shown above.

5 0

3 years ago

A tree is standing in the middle of a meadow. As you watch, the wind begins

Klio2033 [76]

Answer:

B) The tree was stationary and began to move.

Explanation:

This situation can be explained by using Newton's first law of motion, which states that

"An object at rest (or in motion at constant velocity) stays at rest (or in motion at constant velocity) unless a net non-zero force is exerted on it"

This means that an object at rest can start moving if and only if there is a net non-zero force acting on it.

In the example in the problem, the tree is initially stationary. Later, it started to move. According to Newton's first law, therefore, there must be a net force that caused this change of state of motion of the tree. Therefore, the correct answer is

B) The tree was stationary and began to move.

8 0

3 years ago

Three capacitors are connected as follows: 2.8 F capacitor and 5.57 F capacitor are connected in series, then that combination i

DedPeter [7]

ANSWER

8.99 F

EXPLANATION

We know that two capacitors of capacitances 2.8 F and 5.57 F are connected in series, while a third capacitor of capacitance 7.13 F is connected in parallel to that combination,

The capacitance works similarly to the resistance, except that when capacitors are connected in parallel, their capacitances add up, while when they are connected in series, the equivalent capacitance is like we were finding the equivalent resistance of resistors connected in parallel,

$C_{eq}=\frac{1}{\frac{1}{C_1}+\frac{1}{C_2}}+C_3=\frac{1}{\frac{1}{2.8F}+\frac{1}{5.57F}}+7.13F\approx8.99F$

Hence, the total capacitance is 8.99 F, rounded to the nearest hundredth.

6 0

2 years ago