The horizontal branch (HB) is a stage of stellar evolution that immediately follows the red-giant branch in stars whose masses are similar to the Sun's. Horizontal-branch stars are powered by helium fusion in the core (via the triple-alpha process) and by hydrogen fusion (via the CNO cycle) in a shell surrounding the core. The onset of core helium fusion at the tip of the red-giant branch causes substantial changes in stellar structure, resulting in an overall reduction in luminosity, some contraction of the stellar envelope, and the surface reaching higher temperatures.
An object rolls down a smooth plane (whose angle and length are given) starting from rest. At the end of the plane it reaches horizontal rough surface, it rolls again on this surface and comes to rest. Given the friction coefficient how do we calculate the distance traveled by the object on...
For which value of x...horizontal Tangent Line
Homework Statement
For which value of x does f(x) = \frac{k}{ax^{2}+bx+c} have a horizontal tangent line?
Homework Equations
Quotient Rule?
F'(x) = [g(x)a'(x) - a(x)g'(x)]/g(x)^2?
The Attempt at a Solution
Am I supposed to...
hey guys,
i studied "applied maths" in "high school" [the irish version!]
we studied projectile motion and velocity vectors etc,
we worked on the premise that gravity affects only the verticle velocity of the projectile
so that:
for a projectile given an initial velcoity both horizontally...
Hi all..
Currently I'm mess up myself with a study of an improvement of incineration fly ash deposition in horizontal circular ducting hapen in my incineration plant. This plant treated the hazardous industrial waste as a fuel using fludised bed reactor and silica sand as an innert...
Homework Statement
A plane traveling horizontally passes overhead at a height h at t=0. at time t=t1 a sonic boom i heard.
b.) Determine the speed of the Plane
Ma=1/sin(pheta)
pheta=arctan(h/x)
Ma=1/sin(arctan h/vt)
I think I've done it correct up to this point...
Do i have to...
Homework Statement
A mass of 100kg is suspended by two ropes that make angles of 60° to the horizontal. If a horizontal pull of 200N, in a plane perpendicular to the plane of the other forces is applied find the tension in the ropes after equilibrium has occurred.
m=60kg...
Homework Statement
A moving 2.7 kg block collides with a horizontal spring whose spring constant is 356 N/m.
The block compresses the spring a maximum distance of 13.0 cm from its rest postion. The coefficient of kinetic friction between the block and the horizontal surface is 0.24. What is...
[SOLVED] The Flea
Homework Statement
A flea, jumping with its highest possible initial speed, can jump to a maximum vertical height of 1 cm. What is
the time spent in the air by the flea during the vertical jump? What would be the time spent in the air if the flea
were instead to leave the...
Homework Statement
A world-class sprinter can burst out of the blocks to essentially top speed (of about 11.5m/s) in the first 15.0m of the race.
a.) What is the average acceleration of this sprinter?
b.) How long does it take her to reach that speed?
Homework Equations
The...
[SOLVED] Tension with horizontal kinetic friction
Homework Statement
In Figure, block 1 of mass m1 = 1.8 kg and block 2 of mass m2 = 1.3 kg are connected by a string of negligible mass. Block 2 is pushed by force of magnitude 20 N and angle θ = 39°. The coefficient of kinetic friction between...
Homework Statement
A ball is thrown into the air with an initial vertical velocity of 5.0m/s in addition to its horizontal velocity of 25.0m/s, how far would the ball travel horizontally before it reached it's peak?
Homework Equations
vf = vi + at
I've also tried vf = 1/2g +at...
[SOLVED] Projectile and Horizontal Distance
Homework Statement
A projectile launched at an angle \theta to the horizontal reaches a maximum height h. Show that its horizontal range is 4h/tan\theta
Homework Equations
Can you help me figure out how to get this setup properly and what...
1. a table is being sanded. in the process, the sandpaper is rubbed back and forth 30 times over a distance of 0.6m. it is pressed against the table with a normal force of 1.5N, and the coefficient of kinetic friction is 0.85. how much work is being done by the kinetic frictional force during...
vertical and horizontal asymptotes of the curve of f(x) = (x^2+x-6)/(9-x^2 ) are respectively :
a) x=3,x=-3,y=-1 b)x=3,y=-1 c)x=3,y=1 d)x=-3,y=-1
i did the infinit limit to find the horizontal asymptote and i got -1
then to solve the vertical; 9-x^2 = 0 and...
Hi all,
I'm wondering why we see those horizontal and vertical stripes of lights when looking at a light source (see e.g. http://apod.nasa.gov/apod/image/0601/pleiades_gendler_big.jpg" ). Why are these lines of light present in the first place and why are they only horizontal and vertical in...
Recently a thin black horizontal line appeared across my computer screen. At first it was there for a while then went away, now it seems to be permanently there. Anyone know why it is there or how to get get rid of it.
Homework Statement
You use 30N (**Not 25 N, that was a typo) to slide a wooden box that is 12 kg across a floor at constant velocity. What is the coefficient of kinetic fricition?
Homework Equations
Ff=coeff of kinetic friction (mu k) m*g
?? not sure.
The Attempt at a Solution...
1. A 41g object is attached to a horizontal spring with a spring constant of 15N/m and released from rest with an amplitude of 22.4cm. What is the velocity of the object when it is halfway to the equilibrium position if the surface is frictionless? Answer in units of m/s.
Homework Equations...
A hiker plans to swing on a rope across a ravine in the mountains, as illustrated in the figure, where L = 4.9 m and x = 2.7 m, and to drop when she is just above the far edge. At what minimum horizontal speed should she be moving when she starts to swing(in m/s)?
I tried using the...
Homework Statement
A small rock of mass m is kicked from the edge of a perfectly vertical cliff of height h, giving
it an initial velocity ~vo that’s purely horizontal. The rock lands at a distance d away from
the bottom of the cliff. The ground there is assumed horizontal and we neglect air...
We have a spring-mass system which oscillates in one dimension on a frictionless horizontal surface. We act an external force on the mass. F=kχo sin(ωt). Let x=Asin(ωt+φ),A>0 and ωο is the natural frequency of the system.
a) What is the phase of the motion of the mass relatively to the phase of...
3. A 52.3-kg trunk is pushed 5.95m at constant speed up a 28.0 degree incline by a constant horizontal force. The coefficient of kinetic friction between the trunk and the incline is .19 . Calculate the work done by a) the applied force and b) the force of gravity.
Fy = N - mgcos28 = 0
Fx =...
Homework Statement
An air track glider attached to a spring oscillates with a period of 1.5s AT t= 0s the glider is 5.0 cm left of the equilibrium position and moving to the right at 36.3 cm/s
so from what the question i have determined that T = 1.5s x= -0.05m V_x = 0.363m/s
t = 0
Find...
Homework Statement
A box (mass = 50.0 kg) is being pulled up a ramp at an angle of (27 ⁰) by a horizontal force, (F→).
Given that the coefficient of kinetic friction for the ramp is 0.3, find the force, (F→) on the box.
What is the reaction force on the box due to the tramp? (Identify...
[SOLVED] a question
a railcart moves along a railway at constant velocity v_0 with a ball attached to its ceiling. at t=0 the ball is drooped from the ceiling and at the same time the railcart breaks are pushed creating deceleration such that its velocity is:
v=v_0e^{ -pt}\hat{x} .
h is the...
Homework Statement
A 30 kg chandelier hangs vertically from a 4 m long wire. What is the horizontal force necessary to displace the chandelier 0.10 m either way?
Homework Equations
F=ma
The Attempt at a Solution
I tried to figure out the angle made by the change in the...
Homework Statement
A block of mass m is attached to the end of a horizontally mounted spring as shown.
The spring has a spring constant k and obeys Hooke’s law. The block is given an initial
displacement xo, after which it oscillates back and forth without frictional effects.
(a)...
centripetal accel -- airplane flying in a horizontal circle...
Homework Statement
An airplane is flying in a horizontal circle at a speed of 116 m/s. The 77.0 kg pilot does not want his centripetal acceleration to exceed 6.00 times free-fall acceleration.
(a) What is the minimum radius...
Homework Statement
A block of mass m lies on a horizontal table.
Suppose you push horizontally with precisely enough force to make the block start to move, and you continue to apply the same amount of force even after it starts moving.
Find the acceleration of the block after it...
Homework Statement
A weightless ladder at 7m long rests against a frictionless wall at an angle of 65degrees to the ground. A 72kg person is 1.2m from the top of the ladder. What horizontal force at the bottom of the ladder is required to keep it from slipping?
d= 7m
m(man) = 72kg
r(man) =...
Homework Statement
Its not a very difficult problem, and I really only need to know 1 thing about friction; anyways, here's the summed up problem:
(my teacher enjoys making us use constants instead of numbers btw)
A horizontal force F is applied to a small block (mass m1), and it slides...
[SOLVED] Horizontal Speed of bullet fragment
Homework Statement
A 14-kg shell is fired from a gun with a muzzle velocity 125 m/s at 33o above the horizontal. At the top of the trajectory, the shell explodes into two fragments of equal mass. One fragment, whose speed immediately after the...
Homework Statement
A 250 g block is resting on a frictionless horizontal surface. The block is attached to a
spring. The mass-spring system is compressed by a 2.5 N force and then released from
rest.
(a) The resulting oscillation has a 1.0 s period. What is the spring constant?
(b) What is...
Homework Statement
There is a heavy box across the floor, and you apply a horizontal force just sufficient to get the box moving. As the box starts moving, you continue to apply the same force. Show that the acceleration of the box, once it gets started, is
a=(us-uk)*g
Homework...
[SOLVED] A woman pulls a suitcase..what is the angle with the horizontal?
Homework Statement
A woman at the airport tows her 20.0kg suitcase at constant speed by pulling on strap angle theta above the horizontal. She pulls on the strap with 35.0N force. The frictional force on suitcase is...
Homework Statement
What would happen to the coefficient of friction if the applied force was not horizontal to the surface?
Homework Equations
Ff=_{\mu}FnThe Attempt at a Solution
I am unsure of how to proceed with this question, but I am thinking that you can't have friction against a...
using \frac{v_0^2}{g_0}=R_{max} for this problem:
You buy a toy dart gun and you want to calculate its Max Horizontal Range. You fire the gun straight upward and find that it takes 2.9 seconds for the dart to leave the barrel and then return to the barrel.
Can this be done without the...
This is a general question and one that I cannot get an answer for.
What is the difference between the 2?
How do they alter how we approach to solve a problem for each type?
Answers kindly welcomed
Okay here is the problem:
A dart gun is fired while being held horizontally at a height of 1.55 m above ground level, and at rest relative to the ground. The dart from the gun travels a horizontal distance of 7.77 m. A child holds the same gun in a horizontal position while sliding down a 39.7...
A 125 kg mail bag hangs by a vertical rope 3.3 m long. A postal worker then displaces the bag to a position 2.0 m sideways from its original position, always keeping the rope taut.
a)What horizontal force is necessary to hold the bag in the new position?
b)As the bag is moved to this...
"At what points, if any, are the tangents to the graph f(x)=x^2-3x horizontal?"
I know how to figure this out using a graphing calculator and using the 'short-cut' (nx^n-1), but I can't do it using limits. Help!
I'd like to use the equation lim x->a = f(x) - f(a) / x - a
Thanks!
Homework Statement
A person standing on a cliff throws a stone with a horizontal velocity of 15.0m/s and the stone hits the ground 47.0 m from the base of the cliff.
A. How much time does it take for the stone to hit the ground?
B. How high is the cliff?
C. What was the impact velocity of...
Homework Statement
a person sstanding on a cliff throws a stone with a stone horizontal velocoty of 15.0m/s
and the stone lands on the ground 47.0m from the base of the cliff.
a. how much time does it take for the stone to hit the ground?
b. how high was the cliff?
c.what is the impact...
if an object is fired at a 20 degree angle and has a horizontal velocity of 30m/s, what is the vertical displacement, how long the ball is in the air, horizontal displacement, original velocity of the ball?
Homework Statement
A simple pendulum (sting has no mass, no air resistance) has a weight on the end of mass m (unknown). The string has a length A horizontal (and always horizontal) force, F, acts on the weight, but it moves so slowly that acceleration is 0.
a)What is the work done by force...
Homework Statement
A man stands on the roof of a building of height 14.1 m and throws a rock with a velocity of magnitude 31.6 m/s at an angle of 25.0 above the horizontal. You can ignore air resistance.
Calculate the maximum height above the roof reached by the rock.
Calculate the magnitude...
Horizontal Projectile Motion Question...please help!
1. A ball is thrown horizontally from the top of a building 22.8 m. high. The ball strikes the ground at a point 52.1 m. from the base of the building.
a. Find the time the ball is in motion.
b. Find the initial velocity of the ball.
c...
Want to make sure I'm doing this right... it seems too easy
Homework Statement
A horizontal rope is tightly tied to hooks between two walls separated by a distance of 5m. A 100N weight is suspended from the middle of the rope and it sags so that the middle of the rope is displaced a...
Homework Statement
In general, I know that the dynamic equation of pendulum is
theta'' + (k/m)*thata' + (g/l)*sin(theta) = 0
, where k=friction co, m=mass, l=length of string, g=gravity.
But if the pendulum is placed in a constant draft, the equation has to be changed.
Assuming...
A football is thrown upward at a(n) 43 degree angle
to the horizontal.
The acceleration of gravity is 9.8 ms^2 :
To throw a(n) 77.8 m pass, what must be
the initial speed of the ball? Answer in units
of ms.