Subtract the following and give the answer using significant figures 3.400-0.7591

Please help me with my quiz

Oduvanchick [21]

Answer:

matter: A

data: E

variable: C

Controlled: D

Physical: B

Explanation:

8 0

2 years ago

1. A man walks round a park, first walking north for 80m, then turning right and walking

drek231 [11]

Answer:

Total distance travelled = 210m

Explanation:

Distance travelled = 80m + 50m + 10m + 70m

= 210m

8 0

3 years ago

Which of the following are important biotic factors that can affect the structure and organization of biological communities?

umka21 [38]

Answer:

c. predation, competition, parasitism

Explanation:

The important and only biotic factors from the given choices that can affect the structure and organization of biological communities are predation, competition and parasitism.

These factors ensures that there are interaction between organisms of the same and different species and only occur in life.

Biotic factors are the living component of the ecosystem that dictates what happens therein.

Predation is an interaction between two organisms in which the predator, bigger organism feeds on the prey, smaller organism.
Competition occurs where two organism of the same or different species struggles for limited resources in the ecosystem.
Parasitism is an interaction where one organism feeds on the another and it causes harm to it. The organism feeding on another is called the parasite. And the one it is dependent on is the host.

All of these are biotic factors.

3 0

2 years ago

After flying for 15 min in a wind blowing 42 km/h at an angle of 19° south of east, an airplane pilot is over a town that is 48

masha68 [24]

Answer:

The speed of the airplane relative to the air is 209.47km/hr

Explanation:

Whenever we are solving a physics problem, it's really useful to start by drawing a diagram of the problem (See picture attached). It will help us visualize the problem better.

Now, we know that the plane flew for an amount of time of 15 minutes. For our dimensions to be the same, we need to turn those 15min to hours, like this:

$15min*\frac{1hr}{60min}=0.25hr$

Once our time is rewritten as hours, we can now calculate the velocity towards north of the plane.

$V=\frac{distance}{time}$

the plane traveled a distance to the north of 48km so the velocity is:

$V=\frac{48km}{0.25hr}$

so

V=192km/hr j

Now, we can calculate the x and y-components of the velocity of the wind. The problem states that the wind is blowing at 42km/hr at an angle of 19° south of east, so the x and y-components of the velocity of the wind are:

$V_{x}=42km/hr*cos(-19^{o} )=39.71 i$

and

$V_{y}=42km/hr*sin(-19^{o} )=-13.67 j$

So the velocity of the wind can be expressed as a vector as:

$V_{wind}=(39.71i - 13.67j)km/hr$

Once we know this, we can find the velocity of the plane with respect of the wind on x and on y:

$V_{plane x}=V_{plane/wind x}+V_{wind x}$

$V_{plane/wind x}=V_{plane x}-V_{wind x}$

$V_{plane/wind x}=(0-39.71 i)km/hr$

$V_{plane/wind x}= -39.71 i km/hr$

and

$V_{plane y}=V_{plane/wind y}+V_{wind y}$

$V_{plane/wind y}=V_{plane y}-V_{wind y}$

$V_{plane/wind y}=192km/hr j - (- 13.67j)km/hr$

$V_{plane/wind x}= 205.67 j km/hr$

So the velocity of the plane with respect to the wind can be rewritten as:

$V_{plane/wind x}= (-39.71i + 205.67 j) km/hr$

Since the problem asks us to find the speed of the plane with respect to the wind, this means that we need to find the magnitude of the velocity, since the speed is a scalar defined to be the magnitude of the velocity.

so:

$speed=\sqrt{(-39.71)^{2}+(205.67)^{2} }$

speed= 209.47 km/hr

Therefore, the speed of the airplane relative to the air is 209.47km/hr

6 0

3 years ago

Two planets have the same surface gravity, but planet B has twice the mass of planet A. If planet A has mass m, what is the mass

strojnjashka [21]

If B has twice the mass the answer is 2M

5 0

2 years ago