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3 years ago

Can someone explain this please? (:

Physics

1 answer:

topjm [15]3 years ago

8 0

Answer:

a= kinetic energy vs. different masses at same speed, b= kinetic energy vs. same masses at different speeds

Explanation:

graphs are looking at speed so masses don't matter as much. same speed the whole time will equal same kinetic energy the whole time.

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An optical fiber is 1.0 meter long and has a diameter of 20 μm. Its ends are perpendicular to its axis. Its index of refraction

scoundrel [369]

Complete Question

The complete question is shown on the first uploaded image

Answer:

The answer is a

Explanation:

The explanation is shown on the second uploaded image

6 0

3 years ago

A plastic film moves over two drums. During a 4-s interval the speed of the tape is increased uniformly from v0 = 2ft/s to v1 =

Ratling [72]

Answer:

Question 1)

a) The speed of the drums is increased from 2 ft/s to 4 ft/s in 4 s. From the below kinematic equations the acceleration of the drums can be determined.

$v_1 = v_0 + at \\4 = 2 + 4a\\a = 0.5~ft/s^2$

This is the linear acceleration of the drums. Since the tape does not slip on the drums, by the rule of rolling without slipping,

$v = \omega R\\a = \alpha R$

where α is the angular acceleration.

In order to continue this question, the radius of the drums should be given.

Let us denote the radius of the drums as R, the angular acceleration of drum B is

α = 0.5/R.

b) The distance travelled by the drums can be found by the following kinematics formula:

$v_1^2 = v_0^2 + 2ax\\4^2 = 2^2 + 2(0.5)x\\x = 12 ft$

One revolution is equal to the circumference of the drum. So, total number of revolutions is

$x / (2\pi R) = 6/(\pi R)$

Question 2)

a) In a rocket propulsion question, the acceleration of the rocket can be found by the following formula:

$a = \frac{dv}{dt} = -\frac{v_{fuel}}{m}\frac{dm}{dt} = -\frac{13000}{2600}25 = 125~ft/s^2$

b) $a = -\frac{v_{fuel}}{m}\frac{dm}{dt} = - \frac{13000}{400}25 = 812.5~ft/s^2$

5 0

4 years ago

You are running at a speed of 10km/h and hit a patch of mud. Two seconds later you speed is 8km/h. What is your acceleration in

Vlad1618 [11]

Answer:

$0.28 m/s^2$

Explanation:

Acceleration is given by

$a=\frac{v-u}{t}$

where

u is the initial velocity

v is the final velocity

t is the time interval

In this problem:

$u = 10 km/h \cdot \frac{1000 m/km}{3600 s/h}=2.78 m/s$ is the initial velocity

$v = 8 km/h \cdot \frac{1000 m/km}{3600 s/h}= 2.22 m/s$ is the final velocity

t = 2 s is the time

Substituting, we find the acceleration:

$a=\frac{2.78-2.22}{2}=0.28 m/s^2$

5 0

4 years ago

A woman is standing in the ocean, and she notices that after a wavecrest passes, five more crests pass in a time of 50.0 s. Thed

Vadim26 [7]

Answer:

(a) T = 10 s

(b) f = 0.1 Hz

(d) v = 3.2 m/s

(e) Insufficient data

Explanation:

(a)

Time period is defined as the time interval required for one wave to pass. Therefore, the time period can be given as:

T = Period = Time Taken/No. of Waves

T = 50 s/5

T = 10 s

(b)

Frequency is the reciprocal of time period:

f = frequency = 1/T

f = 1/10 s

f = 0.1 Hz

(c)

Wavelength is the distance between two consecutive crests or troughs:

λ = Wavelength = 32 m

(d)

Speed of wave is given by the following formula:

Speed = v = fλ

v = (0.1 Hz)(32 m)

v = 3.2 m/s

(e)

Amplitude cannot be found with given data.

6 0

3 years ago

Explain why the speed of light is lower than 3.0 x 108 m/s as it goes through different media.

jekas [21]

Answer:

Sample Response: In a vacuum, there are no atoms or particles that interfere with the path of light. However, in other media, the speed of light is lower than 3.0 × 108 m/s because the wave is continuously absorbed and re-emitted by each atom in its path. The differences in speed are due to the composition of the medium and the density of the particles in the medium.

Explanation:

7 0

4 years ago