All categories

3 years ago

1) Choose the answer choice that BEST completes the following sentence.

Physics

2 answers:

Lena [83]3 years ago

5 0

1. one-Half

2. Apogee

3. Any object that revolves around another object

4. Venus's gravitation pull

dimulka [17.4K]3 years ago

3 0

Answer:

1) (d)

2 (a)

3 (d)

4 (d)

Explanation:

1) Like earth, sun also illuminates half of the moon 's surface at a time.

2) The point on the earth orbit which is closest to the earth is called perigee.

3) Any object that revolves around another object in space is called satellite.

4) Venus has very little effect on the formation of tide on the earth as it is far off from it.

You might be interested in

An electric motor can drive grinding wheel at two different speeds. When set to high the angular speed is 2000 rpm. The wheel tu

shutvik [7]

a) The initial angular speed is 209.3 m/s

b) The angular acceleration is $-1.74 rad/s^2$

c) The angular speed after 40 s is 139.7 rad/s

d) The wheel makes 1501 revolutions

Explanation:

The initial angular speed of the wheel is

$\omega_i = 2000 rpm$

which means 2000 revolutions per minute.

We have to convert it into rad/s. Keeping in mind that:

$1 rev = 2\pi rad$

$1 min = 60 s$

We find:

$\omega_i = 2000 \frac{rev}{min} \cdot \frac{2\pi rad/rev}{60 s/min}=209.3 rad/s$

To find the angular acceleration, we have to convert the final angular speed also from rev/min to rad/s.

Using the same procedure used in part a),

$\omega_f = 1000 \frac{rev}{min} \cdot \frac{2\pi rad/rev}{60 s/min}=104.7 rad/s$

Now we can find the angular acceleration, given by

$\alpha = \frac{\omega_f - \omega_i}{t}$

where

$\omega_i = 209.3 rad/s$ is the initial angular speed

$\omega_f = 104.7 rad/s$ is the final angular speed

t = 60 s is the time interval

Substituting,

$\alpha = \frac{104.7-209.3}{60}=-1.74 rad/s^2$

To find the angular speed 40 seconds after the initial moment, we use the equivalent of the suvat equations for circular motion:

$\omega' = \omega_i + \alpha t$

where we have

$\omega_i = 209.3 rad/s$

$\alpha = -1.74 rad/s^2$

And substituting t = 40 s, we find

$\omega' = 209.3 + (-1.74)(40)=139.7 rad/s$

The angular displacement of the wheel in a certain time interval t is given by

$\theta=\omega_i t + \frac{1}{2}\alpha t^2$

where

$\omega_i = 209.3 rad/s$

$\alpha = -1.74 rad/s^2$

And substituting t = 60 s, we find:

$\theta=(209.3)(60) + \frac{1}{2}(-1.74)(60)^2=9426 rad$

So, the wheel turns 9426 radians in the 60 seconds of slowing down. Converting this value into revolutions,

$\theta = \frac{9426 rad}{2\pi rad/rev}=1501 rev$

Learn more about circular motion:

brainly.com/question/2562955

brainly.com/question/6372960

#LearnwithBrainly

8 0

3 years ago

A small child has a wagon with a mass of 10 kilograms. The child pulls on the wagon with a force of 2 newtons. What is the accel

notka56 [123]

Explanation:

F = ma

2 N = (10 kg) a

a = 0.2 m/s²

6 0

3 years ago

The light which allows you to see this very interesting exam is made up of waves. In these waves, the distance between crests is

lakkis [162]

Answer:

idk

Explanation:

idk

5 0

3 years ago

Read 2 more answers

Suppose an astronaut in outer space wishes to toss a ball against a very massive and perfectly elastic concrete wall and catch i

madam [21]

Answer:

B. the astronaut will never catch the first bounce.

Explanation:

7 0

3 years ago

(a) Neil A. Armstrong was the first person to walk on the moon. The distance between the earth and the moon is 3.85 x 108 m. Fin

gizmo_the_mogwai [7]

Answer:

a). 1.28333 seconds

b). 186.66 seconds

Explanation:

a). Given :

Distance between the earth and the moon, d = $3.85 \times 10^8$ m

Speed of the radio waves, c = $3 \times 10^8$ m/s

Therefore the time required for the voice of Neil Armstrong to reach the earth via radio waves is given by :

$t=\frac{d}{c}$

$=\frac{3.85 \times 10^8}{3 \times 10^8}$

= 1.28333 seconds

b). Distance between Mars and the earth, d = $5.6 \times 10^{10}$ m

Speed of the radio waves, c = $3 \times 10^8$ m/s

So, the time required for his voice to reach earth is :

$t=\frac{d}{c}$

$=\frac{5.6 \times 10^{10}}{3 \times 10^8}$

= 186.66 seconds

6 0

3 years ago