1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Valentin [98]
1 year ago
13

The mass of a star is 1.210×1031 kg and it performs one rotation in 20.30 days. Find its new period (in days) if the diameter su

ddenly shrinks to 0.350 times its present size. Assume a uniform mass distribution before and after.
Physics
1 answer:
balandron [24]1 year ago
8 0

The new period will be 2.486 days.

<h3>What is the period?</h3>

The period is found as the ratio of the angular displacement and the angular velocity. Its unit is the second and is denoted by t. The value of time needed to complete the rotation is the total period.

Given data;

Mass of a star,m= 1.210×10³¹ kg

The time period for one rotation of the star, T = 20.30 days

D' = 0.350 D

R' = 0.350 R

From the law of conservation of angular momentum;

\rm  I \omega = I' \omega' \\\\ \frac{2}{5} MR^2 \times \frac{2 \pi }{T}=\frac{2}{5} MR'^2 \\\\ R^2 \times \frac{1}{T}= R'^2  \times \frac{1}{T} \\\\ T' = \frac{R'^2T}{R^2}  \\\\ T' = \frac{(0.350 R)^2 \times 26.1 }{R^2} \\\\T' = 0.1225 \times 20.30 \\\\ T'= 2.486 \ days

Hence, the new period will be 2.486 days.

To learn more about the period, refer to the link;

brainly.com/question/569003

#SPJ1

You might be interested in
a 5.5 g dart is fired into a block of wood with a mass of 22.6 g. the wood block is initially at rest on a 1.5 m tall post. afte
IgorLugansk [536]
<span>From the problem alone we can say that the dart and the block of wood combined into a single object moving together at the end. With that clue we know that the collision is an inelastic collision. The formula of an inelastic collision is:

m_{1}v_{1i}+m_{2}v_{2i}=(m_{1}+m_{2})v_{f}

First let us sort out our given:Mass should be in kg to get the proper answer. Now let's assign m1 as the mass of the dart and m2 as the mass of the block. 
m1 = 5.5g

5.5g x \frac{1kg}{1000g}= 0.0055kg

m2 = 22.6g

22.6g x \frac{1kg}{1000g}= 0.0226kg

So now we settled that we can set our given as:
M1 = .0055 kg
v1i = ?
M2 = 0.0226 kg
v2i = 0 m/s
dx = 2.5 m
dy = -1.5 m

Now you can see that we have 2 unknowns: v1i and vf. We need the vf to solve for the initial velocity of the dart or object 1. We have other given to consider, so we can make use of that to get our missing vf. 

Now, vf is the horizontal velocity after the collision. We do this by first using the equations for projectiles considering that we have an x and y dimension to consider. We use the y dimension to get the x. 
</span>

dy = -1.5 m 

a = 9.8m/s^2

viy = 0 (take note that the initial vertical velocity is 0)

t = ?

<span>We can use the UAM equations to solve for the time in the y-dimension (vertical) to get the horizontal velocity. 

dy = v_{iy}t +  \frac{1}{2} at^{2}</span>

1.5 = (0)t+\frac{1}{2} (9.8)t^{2}

<span>1.5 = \frac{1}{2} (9.8)t^{2}

\frac{(2)(1.5)}{9.8}=t^{2}

\frac{(3)}{9.8}=t^{2}

\sqrt{0.3061} = \sqrt{t^{2}

0.553s = t

Now using this, we can get the horizontal (x-dimension) velocity using the formula:
v_{x} =d_{x}t and our given earlier for the horizontal distance is 2.5m and we solved for time 0.553s. Let's put that into our equation:
v_{x} =d_{x}t
v_{x} =(2.5m)(0.553s) 
v_{x} =4.52m/s

Now we finally have our vf or velocity after the collision. Now let's get back to the equation.

m_{1}v_{1i}+m_{2}v_{2i}=(m_{1}+m_{2})v_{f}

From this we can derive the equation for v1i by isolating it. 

v_{1i}= \frac{((m_{1}+m_{2})v_{f})-(m_{2}v_{2i})}{m_{1}}

Now let's put in all our given and what we solved:

v_{1i}= \frac{((0.0055kg+0.0226kg)4.52m/s)-((0.0226kg)0m/s)}{0.0055kg}

v_{1i}= \frac{(0.0281kg)4.52m/s)}{0.0055kg}

v_{1i}= \frac{0.127012kg.m/s}{0.0055kg}

v_{1i}= 23.09m/s

The initial speed of the dart is 23.09 m/s or 23.10 m/s.</span>
7 0
3 years ago
(b) Find the position, velocity, and acceleration of the mass at time t = 5π/6.
Juli2301 [7.4K]
Solution 
x(t) = 8 cos t, x(5π/6)= 8 cos(<span>5π/6)
</span>cos(5π/6)=cos(3π/6 + 2π/6 )=cos(π/3 +π/2)= - sin π/3  (cos (x+<span>π/2)= -sinx)
</span>x(t) = -8sin <span>π/3 = - 4 .sqrt3
</span>v(t) = -8sint = -8sin (π/3 +<span>π/2)= -8 cosπ/3 </span>(sin (x+π/2)= cosx)
v(t) =<span> -8 cosπ/3 = -8/2= - 4 
</span>a(5π/6) = - 8cost = -(- sin π/3)= 4 .<span>sqrt3
</span>a(5π/6) =  4 .<span>sqrt3</span>
4 0
3 years ago
A 2.0 kg puck is at rest on a level table. It is pushed straight north with a constant force of 5N for 1.50 s and then let go. H
lukranit [14]

Answer:

d = 6.32 m

Explanation:

Given that,

The mass of a puck, m = 2 kg

It is pushed straight north with a constant force of 5N for 1.50 s and then let go.

We need to find the distance covered by the puck when move from rest in 2.25 s.

We know that,

F = ma

a=\dfrac{F}{m}\\\\a=\dfrac{5}{2}\\\\a=2.5\ m/s^2

Let d is the distance moved in 2.25 s. Using second equation of motion,

d=ut+\dfrac{1}{2}at^2\\\\d=0+\dfrac{1}{2}\times 2.5\times (2.25)^2\\\\d=6.32\ m

So, it will move 6.32 m from rest in 2.25 seconds.

4 0
2 years ago
Sara is riding her bike down the road at 35 km/hr. She starts to peddle faster as she
steposvetlana [31]

Answer:

Distance covered to top of the hill was : 1.755 km

Explanation:

Initial velocity = 35 km/hr

Acceleration = 2.0 km/hr²

Time taken to accelerate = 3 minutes = 3/60 hours = 1/20 hours

Formula for acceleration : a = Δv /t  

v-u/t    ---where u is initial velocity , v is final velocity and t is time taken for acceleration

v- 35 / 0.05 = 2

v = 35.10 km/h

Formula for distance is product of speed and time

Distance covered = 35.10 * 0.05 = 1.755 km

6 0
2 years ago
Analyze how buffers allow you to eat acidic and basic foods without changing your blood pH.
blondinia [14]
Buffers neutralize the acid and the bases
7 0
3 years ago
Other questions:
  • 1. A soccer ball is kicked at ground level at 30 m/s at an angle of 53° to the horizontal.   a. How far away does it land? b. Ho
    11·1 answer
  • The force on a wire is a maximum of6.71 10-2 N when placed between the pole faces of a magnet.The current flows horizontally to
    7·1 answer
  • A certain gas is present in a 15.0 l cylinder at 2.0 atm pressure. if the pressure is increased to 4.0 atm the volume of the gas
    15·1 answer
  • Which of the following is a temporary magnet made by placing a piece of iron inside a current-carrying coil of wire
    8·1 answer
  • A dog sits 1.5 m from the center of a merry-go-round. The merry-go-round is set in motion, and the dog's tangential speed is 1.5
    14·1 answer
  • Helium is an odorless, colorless gas at room temperature. It is less dense than air. That's why helium balloons float. It is a n
    11·2 answers
  • PLEASE HELP ASAP!!! CORRECT ANSWERS ONLY PLEASE!!!
    15·2 answers
  • A car travels along a straight road at a steady 40 MPH.Are the forces on the car balanced or unbalanced? Explain.
    12·1 answer
  • Which of the following has the highest viscosity? A. corn syrup B. milk C. water D. orange juice
    15·1 answer
  • A person raises a box with a weight of 50 newtons by 0.5 meter. How much work does the person do in this action?(1 point)
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!