What is Change in velocity: Definition and 46 Discussions
Delta-v (more known as "change in velocity"), symbolized as ∆v and pronounced delta-vee, as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such as launching from or landing on a planet or moon, or an in-space orbital maneuver. It is a scalar that has the units of speed. As used in this context, it is not the same as the physical change in velocity of the vehicle.
As a simple example, take a conventional rocket-propelled spacecraft which achieves thrust by burning fuel. The spacecraft's delta-v is the change in velocity that spacecraft can achieve by burning its entire fuel load.
Delta-v is produced by reaction engines, such as rocket engines, and is proportional to the thrust per unit mass and the burn time. It is used to determine the mass of propellant required for the given maneuver through the Tsiolkovsky rocket equation.
For multiple maneuvers, delta-v sums linearly.
For interplanetary missions, delta-v is often plotted on a porkchop plot, which displays the required mission delta-v as a function of launch date.
So consider a subject system, a galaxy, with stars in it. This galaxy is passed by another object, the perturber. When the interaction is fast, we call this interaction a high-speed encounter.
Now we consider that the interaction is really fast. This means that during the interaction, the...
Hi everyone,
The four fundamental forces are gravity (I understand that G.R. does not look upon gravity as a force but I'm not worried about that here), the Lorentz force, the weak force, and the strong force. I'm familiar with the inverse square law for gravitation and the Lorentz force...
We're given the equation qB=mv/r which is simple enough. I just don't know how to find the velocity given the acceleration through a potential difference. I tried using the radial acceleration equation given to me but I end up with the square root of a negative...and that breaks math... I...
Homework Statement
The graph shows the variation with time t of the acceleration a of an object (graph attached).
What is the change in velocity of the object in the time interval 0 to 4s?
Homework Equations
a = v/t
The Attempt at a Solution
My initial answer was -8 m/s, by simply finding the...
Homework Statement
Is it possible for the instantaneous velocity of an object at some time, t1, to not be parallel to the average velocity over a short time interval, Δt=t2-t1? If it is not possible, explain why not. If it is possible, explain what this situation implies about the motion of...
What happens to the velocity?
Say we have a piece of space debris in free fall. It has a particular velocity at a given time. Then say at some later time it's bombarded with ionic gas or something that causes it to become charged. Does the velocity change?
My guess would be yes, because the...
Good afternoon all,
For those of you that teach physics, if an object has an initial velocity of - 5m/s and a final velocity of -20 m/s, do you consider the velocity to be increasing or decreasing in this case?
I view this to be strictly defined mathematically, that is that the acceleration is...
Homework Statement
Homework EquationsThe Attempt at a Solution
[/B]
Assuming the right direction is positive, it hits the wall and reaches point 2, so to get back to point 1, it's in a negative direction, so it should be MINUS 4m so option A but the correct answer is B??
Or is it to do...
Homework Statement
It takes 185 kJ of work to accelerate a car from 23.0 m/s to 28.0 m/s. What is the car’s mass?Homework Equations
E=1/2mv^2
The Attempt at a Solution
I get that I must put (2E) over V2 I am just not sure if I was allowed to put the change in velocity so it would look like...
What change in velocity would be produced by an unbalanced force of 2.4 × 10^4 N acting for 6 s on a 2.0 × 10^3 kg dragster?
Not sure how to setup this problem Equations i have are as follows:
Fnet = mass × acceleration
Velocity2 = velocity1 + acceleration × time
Distance = velocity1 × time +...
Homework Statement
Kevin and Jake collide in the air. If Kevin undergoes a 4.2 kg*m/s change in momentum, what is Jacob’s change in velocity if he has a mass of 83.2 kg?
Homework Equations
p=mv
MV+mv=MV'+mv'
The Attempt at a Solution
I tried the simplest way possible...
p=mv
v=p/m
v=4.2/83.2...
Homework Statement
If an astronaut was in a weighless environment, sitting down and eating a meal, what would happen to the astronaut if the spacecraft decided at that moment to turn on the space craft's main engines and
a) the astronaut was facing the engines?
b) the astronaut's back was to...
Homework Statement
A sailing boat moves at 12ms-1 due North then changing direction to north-west and traveling at a speed of 5.5ms-1 . Determine the magnitude of change in velocity n its direction.
Homework EquationsThe Attempt at a Solution
If the velocity of the object of 5 kg changed from 5 m/s to 4 m/s. Then is the change in kinetic energy -22.5 J or +22.5J.
doesn't change mean final velocity minus initial velocity?
Homework Statement
A batsman hits a cricket ball traveling towards him at 30m/s over square leg at 50m/s. If the cricketer is facing north and square leg is west of him, what is the change in velocity of the ball?
Homework Equations
Δv= Final velocity subtract initial velocity.
The...
An automobile of mass 1500 kg traveling at 24 m/s crashes into a similar parked automobile. The two automobiles remain joined together after the collision. Suppose that the collision last for 0.020s, and pavement with a coefficient of friction uk=0.63. What change of momentum and what change of...
Homework Statement
The question is: Acceleration versus time graphs for five objects are shown below. All axes have the same scale. Which object had the greatest change in velocity during the interval?2. The attempt at a solution
Not sure how to start here I only know about distance over time...
Homework Statement
A ball of mass 0.150 kg is dropped from rest from a
height of 1.25 m. It rebounds from the floor to reach a
height of 0.960 m. What impulse was given to the ball
by the floor?
Homework Equations
Δmv/t =I
vf^2=vo^2 +2aΔy
The Attempt at a Solution
mghi =...
Homework Statement
A car's velocity changes from 13.9 m/s east to 12.8 m/s northeast. What is the change in it's velocity?
It's a 4 marker.
Homework Equations
The Attempt at a Solution
Honestly, I don't really know how to start this. I know it's a vector difference and I've drawn...
Change in velocity, help please. :)
Homework Statement
A tennis ball’s initial velocity is 30 m/s [S]. When struck by a tennis racquet, its velocity becomes 28 m/s [N30°W]. Determine the ball’s change in velocity.
The Attempt at a Solution
I've used the normal component method but I end up...
Homework Statement
The graph in the figure describes the acceleration as a function of time for a stone rolling down a hill starting from rest.
Find the change in the stone's velocity between 2.5s and 7.5s.
Homework Equations
I think v = v0t +1/2at^2
The Attempt at a Solution
I honestly...
Homework Statement
A rocket is in elliptic orbit about the earth. To put it into escape
velocity, its engine is fired briefly, changing the rocket’s velocity by
deltaV . Where in the orbit, and in what direction, should the firing occur
to attain escape with a minimum value of deltav...
Homework Statement
A 15 kg cart is moving east at 3.0 m/s when 10 kg of newspaper is vertically dropped into the cart. Find final veocity?[b]2. Homework Equations [/b
m1v1i+m2v2i=m1v1f+m2v2f
Kinematic eqs and trig will be necessary to find components for the 10kgnewspaper
The Attempt at a...
Homework Statement
A turntable has a moment of inertia of 2.5 x 10-2 kg m2 and spins freely at 33.3 rev/min. A 0.25 kg ball of putty is dropped vertically on the turntable at a point 0.20 m from the center. What is the new angular speed of the system?
a. 41 rev/min
b. 24 rev/min
c. 33...
Homework Statement
A merry-go-round has a radius of 3.0 m and a rotational inertia of 600 kg m2. The merry-go-round is initially at rest. A 20 kg child is running at 5.0 m/s along a line tangent to the rim. Find the angular velocity of the merry-go-round after the child jumps on.
a. 0.38...
1. If the velocity at the beginning of an interval is 4 m/s and at the end of the interval it is 10 m/s, then what is the average of these velocities, and what is the change in velocity?
Give an example of positive initial and final velocities for which the order of the four quantities...
Homework Statement
At t = 0, an automobile traveling north begins to make a turn. It follows one-quarter of the arc of a circle of radius 10.5 m until, at t = 1.42 s, it is traveling east. The car does not alter its speed during the turn.
Find the car's speed.
Find the change in it's velocity...
hey guys! we know that velocity of a wave = wavelength x frequency. and speed of light changes with change in optical density. so there must be change in either frequency or wavelength or both. which of these quantities change with change in optical density? and why?
Minimum change in velocity! Helpppp?
Homework Statement
Calculate the minimum change in velocity (delta V or ∆V) required for the Space Shuttle to decrease its altitude to 60 miles if it’s orbiting with an apogee of 236 miles and a perigee of 215 miles above the surface of Earth.
Use the...
Here's a question that I got in my mechanics tutorial.
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A particle travels on a semi-circular path from A to B -
The diameter being 200m, the time taken 80 seconds, Calculate:
a) its speed
b) average velocity from...
Homework Statement
What is the acceleration of a bullet that was shot at 40.m/s in the horizontal and then changed to a velocity of 44.5m/s at 26.1* below the horizontal in a time of 2.0 seconds.
Homework Equations
vf-vi= delta v a= delta v / time
The Attempt at...
Nice to meet you all. While this may be my first post here, I will be here quite often for the next year because I'll be taking physics.
Homework Statement
John drives 15 km directly west from Orion to Chester at a speed of 86 km/h, then directly south for 7.0 km to Seiling at a speed of...
Hi everyone,
I'm a doctor who is fair at maths - haven't done physics for a while. I'm trying to model some heart physiology which I can describe as a mechanics problem:
I have a particle, mass m, with a constant force acting on it, f.
It also has resistance R, where the resistance is...
Ok i have the following problem, I have a fan connected to the nozzle, i am given the nozzle area and the volumetric flow rate generated by the fan. How can i find the velocity of the air at different distances from the tip of the nozzle?
any help is greatly appreciated
Homework Statement
Water enters and leaves a pipe as shown at a steady speed of 1.5. Find the change in velocity.
http://kv8v6q.blu.livefilestore.com/y1pjsZ-s4z6_sTZEgW2-nsZ8pf1YrZml2cqcsXxgwnDNbUzFlaPXJcSe_nX93qAi6xd_Z7BATO9oBNXPDbxrGoJHEkk6WbzV3wR/0.bmp
Homework Equations...
Homework Statement
The initial velocity of a ball is 1.0 m/s East (E). The final velocity is 1.0 m/s South (S). The change in the velocity of the ball is?
Homework Equations
(x^2+y^2)^.5
The Attempt at a Solution
would it simply be 1.4 southeast?
Homework Statement
Earth's orbit around the SUn is nearly circular. THe period is 1 year = 365.25 days. In an elapsed time of 2.70 days, what is Earth's angular displacement? what is the change in Earth's velocity (perpendicular to the average velocity) What is the Earth's average acceleration...
Homework Statement
I am required to find the change in velocity given these two vectors:
Va = 4.4 m/s [E31*S]
Vb = 7.8 m/s [E25*N]
Homework Equations
delta V = Vb - Va
delta V = Vb + (-Va)
The Attempt at a Solution
I am stuck between two solutions:
#1. Simply subtracting...
The following diagram shows the path taken by the center of mass of a baseball player sliding along the ground in an attempt to make the base.
The player is moving at a speed of 10m/s just before the slide and his speed 0.5 seconds later is 8.0m/s. The mass of the player is 80kg
1a)...
Homework Statement
An airplane is flying at 2.00 x 10^2 km/h [S30.0W]. It makes a smooth wide turn and heads east at 2.00 x 10^2 km/h. Find its change in velocity.
Homework Equations
v = vf - vi
The Attempt at a Solution
the directions are throwing me off. What do i do after i...
Homework Statement
A spacecraft is initially in a circular orbit of the sun at the Earth's orbital radius. It uses a single brief rocket thrust parallel to it's velocity to put it in a new orbit with aphelion distance equal to the radius of Jupiter's orbit.
What is the ratio of the...
Homework Statement
Find Size and direction of the change in velocity:
a)5m/s west to 10 m/s west
b)10m/s west to 5m/s west
c)5m/s west to 10m/s east
Homework Equations
The Attempt at a Solution
a)10-5= 5 west
b)5-10=-5 because there isn't size wihe negitve the...
can anyone help me:
a van is traveling north at a speed of 28ms-1. after turning a corner its heading is 40 degrees east of north at 25ms-1. workout the change in velocity of the van
9 A softball of mass 0.15 kg traveling at a speed of
16 m s–1 is struck so that it moves away from the bat at
an angle of 45° to its original direction and with the
same speed.
a What is the direction of the change in velocity of the
ball?
how do u work this question out ?
the book told...
2) the driver of a 600kg sports car, heading directly for a railroad crossing 250m away, applies the brakes i a panic stop. the car is moving at 40m/s, and the brakes can supply a friction force of 1200N. a) how fast is the car moving when it reaches the crossing?
- i tried finding the change...