Science
how does a scientist compare the age of a rock with other rocks?

(a) by determining the relative age of the rock

(b) by deciding the exact date the rock was formed

(c) by finding the level of radioactive isotope decay in the rock

(d) by finding the absolute age of the rock

2. which of the following could be used to interpret the geologic history of a location?

(a) human remains

(b) atmospheric components

(c) rock layers

(d) plant life

3. geologists frequently look at the relationships among rock layers. which statement best describes the information geologists get from studying these relationships?

(a) they can tell how old the rocks are.

(b) they get a sense of which rocks are the most valuable.

(c) they get a sense of the history of the area they are investigating.

(d) they can tell how dense the rocks are.

4. which of the following events separate geologic time into eras and periods?

(a)the appearance and disappearance of groups of organisms

(b)the number of earthquakes occurring at that time

(c)the appearance and disappearance of volcanoes

(d)the creation of new ocean ridges

5. which of the following provides evidence that has earth scientists determine the age of the earth more precisely?

(a) tree rings

(b)earth's distance from the sun

(c)helium dating

(d)radioactive dating

6. while collecting samples or rocks, a scientist collects several samples that contain fossils. what is most likely the type of rock in the scientist's samples?

(a)mineral

(b)igneous

(c)sedimentary

(d)metamorphic

7. if a sandstone in contact with a granite contains fragments of the granite, what can you infer?

(a)the granite was intruded into the sandstone.

(b)the granite is older than the sandstone.

(c)the sandstone and granite are the same age.

(d)the granite is younger than the sandstone

(d) by finding the absolute age of the rock

The relative age of a rock is not an exact number or age; rather it's the comparison of one rock or fossil to another to determine which one is older or younger. Scientists use carbon dating to calculate the age of a rock. Organic material from the rock is tested and that information is used to calculate the estimated age.

C) Rock layers

The Fossil Record and Geologic Time Fossils of plants and animals are present in some rocks. These fossils contribute to our understanding of geologic time and they show us the time span when and how a civilization used to live.

(c) They get a sense of the history of the area they are investigating.

Fossils scaled into rocks are fundamental to the geologic time scale. For instance rocks formed during the Proterozoic Eon may have fossils of relative simple organisms, such as bacteria, algae, and wormlike animals while Rocks formed during the Phanerozoic Eon may have fossils of complex animals and plants such as dinosaurs, mammals, and trees.  

(a)the appearance and disappearance of groups of organisms

the appearance and disappearance of groups of organisms in different geological eras of earth history shows the time span of that era. This time span can be easily determined from the fossils present on sedimentary rocks because they show the family or group of those species which were present in that particular time period.

(d)radioactive dating

Scientists use radioactivity techniques to determine the age of earth. As we know radioactive substances emit energy continuously and they have a certain half life period so calculating the half life period can show us the age of earth by comparing the half lives of different radioactive elements. For example in uranium-lead dating, for instance, the radioactive decay of uranium into lead proceeds at a reliable rate.

(c)Sedimentary

Mostly sedimentary rocks like limestone and shale are the best options in the formation of fossils. Igneous rocks are formed directly from hot lava that is why they would not be able to preserve any remnants of living organisms that fall in it during its formation.

The granite is older than the sandstone.

The principle of inclusions states that with sedimentary rocks, if inclusions  are found in a formation, then the inclusions must be older than the formation that contains them. So in simple words pieces of the older rock will be included in the younger rock therefore option B is the correct answer.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

answer: 21

step-by-step explanation:

divide 630 by 30. 30 goes into 630 21 times