Which group contains examples of materials that were not part of a living thing

Cloud [144]

Answer:

(B) Sending Messages

Explanation:

A similarity between radio waves and microwaves is that both are used for sending messages and communication

Radio Waves and Microwaves have longer wavelengths and lower frequencies. Longer wavelengths than an x-ray which is in the electromagnetic spectrum and lower frequencies than gamma rays, which are also in the electromagnetic spectrum. They are also both electromagnetic radiation.

5 0

3 years ago

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The engine in an imaginary sports car can provide constant power to the wheels over a range of speeds from 0 to 70 miles per hou

kirill115 [55]

Answer:

Part A

it would take 6 sec

it would take 3 sec

Explanation:

We are told that the power supplied to the wheel is constant which means that the sport car is gaining energy i.e

$power \ \alpha \ energy$

Hence if power is constantly supplied energy constantly increase

From the formula of the Kinetic energy

$KE = \frac{1}{2} mv^2$

we can see that as the speed doubles from 29 mph to 58 mph the energy needed is $2^2$ = 4 times of the energy from the formula

Also the time needed would also be 4 times because energy i directly proportional to time

Hence to reach 58mph the time that it would take is

= $4* 1.5sec = 6sec$

We are told that the ground pushes the car with a constant force and

F = ma

this means that the acceleration is also constant

now from newtons law

v = u +at

Looking at it we see that final velocity is directly proportional with time

hence it would take twice the time to reach twice the final velocity

Time to reach 58mph = 3 s

since time to reach 29 mph( $\frac{1}{2} \ of \ [58mph]$ ) =( $\frac{1}{2} \ of \ 3sec$ )1.5 s

6 0

3 years ago

Acceleration is directly proportional to which of the following quantities ?

tankabanditka [31]

The answer is D because i'm in the same studies right now.

7 0

3 years ago

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The position of a particle moving along an x axis is given by x = 14.0t2 - 2.00t3, where x is in meters and t is in seconds. det

Mumz [18]

a) x = $14t^{2} -2t^{3}$

at t = 5s

$x = 14*5^{2} -2*5^{3} = 14*25 - 2*125 = 350 - 250 = 100 m$

b) v = $\frac{dx}{dt}$

= $28t - 6t^2$

at t = 5 s

v = $28*5-6*25 = 140 - 150 = -10 m/s$

c) a = $\frac{dv}{dt}$

= 28 - 12t

at t = 5 s

a = 28 -12*5= 28-60= -32 m/ $s^2$

d) At maximum positive coordinate velocity = 0

So, $0 = 28t - 6t^2$

$t = \frac{28}{6} = \frac{14}{3} = 4.66 s$

At t = 4.66 s

$X = 14 * 4.66^2 - 2* 4.66^3 = 202.39 m$

e) At t = 4.66 s

f) At maximum positive velocity a = 0

$0=28-12t$

$t = \frac{28}{12} = \frac{7}{3} = 2.33 s$

At t = 2.33 s

V = $28*2.33- 6*2.33^2= 32.67 m/s$

g) t = 2.33 s

h) When particle is not moving v = 0

So $0= 28t - 6 t^2$

$t = \frac{28}{6} = 4.66 seconds$

At t = 4.66 s

a = $28 - 12 * 4. 66 = -27.93m/s^2$

i) At t = 0s, X =0m

t = 5s, X = 100m

So, Displacement = 100m

Velocity = $\frac{Displacement}{Time} = \frac{100}{5} = 20m/s$

8 0

3 years ago

2. In order to get a Master's degree a

melomori [17]

I don’t know how to answer your question but if you want go to google

7 0

3 years ago