Linear momentum Definition and 327 Threads

1) Calculate the force exerted on a rocket, given that the propelling gases are expelled at a rate of 1500 kg/s with a speed of 4.0 x 10^4 m/s (@ the moment of take off) Answer: 6.0 x 10^7 N Okay I can not figure how to get an equation to use... Though I did noticed that the rate x the speed...

A 0.118 kg mass is moving horizontally with a speed of 8.49 m/s when it strikes a vertical wall. The mass rebounds with a speed of 1.07 m/s. What is the magnitude of the change in linear momentum of the mass? isn't the change just the difference in momentum? I did .118(8.49 - 1.07) to get...

When jumping straight down, you can be seriously injured if you land stiff-legged. One way to avoid injury is to bend your knees upon landing to reduce the force of the impact. A 73.9-kg man just before contact with the ground has a speed of 5.55 m/s. (a) In a stiff-legged landing he comes to a...

Ok, don't ask why I was doing this dynamics problem from an old textbook, but, I cannot get the answer to match that in the back of book and it's a simple problem. Here it is, a cannon weighing 400 lb, fired a cannon ball weighing 10 lb, and had a muzzle velocity of 200 ft/s. For a 10 degree...

Hi everyone, I had a doubt about conservation of linear momentum while doing the following question(I managed to get the right answer but am not sure why my method worked). A bmp file of the problem has been attached. Both blocks shown are confined to move in the horizontal slot. Block B...

I have been missing for class 3days and i was get lost because my daughter gets sick in the past weeks :cry: :( until todate. The problems i need everyone helps below are just a sample exam. I have contact my professor about my family problems and he was nice, gave me the sample exam which it's...

Two friends, Al and Jo, have a combined mass of 168 kg. At an ice skating rink they stand close together on skates, at rest and facing each other, with a compressed spring between them. The spring is kept from pushing them apart because they are holding each other. When they release their arms...

A 0.010-kg bullet traveling horizontally at 400.0 m/s strikes a 4.0-kg block of wood sitting at the edge of a table. The bullet is lodged into the wood. If the table height is 1.2 m, how far from the table does the block hit the floor? this is what i did: lets the mass of bullet = m2 the...

A meteor whose mass was about 10^8 kg struck the Earth (m = 6.0 X10^24 kg) with a speed of about 11 km/s and came to rest in the Earth. (a) What was the Earth's recoil speed? (m/s) (b) What fraction of the meteor's kinetic energy was transformed to kinetic energy of the Earth? (%) (c) By...

The figure (attached) gives the magnitude p of the linear momentum versus time t for a particle moving along an x-axis. A force dircted along the axis acts on the particle (a) Rank the four regions indicated according to the magnitude of the force, greatest first (b) In which regins is the...

Hi all, I have a question. First, a moving ball, ball A, slides straight into a ball which is standing still, ball B. The balls then collide, and ball B rebounds along, say, the Y-axis at a certain speed. Now suppose we recreate the collision, except this time, ball B is spinning on its...

I've stupidly told a friend that I am good at physics, but I am really not. He's set me a question that he wants answering, with an equation. The question is How fast does a car have to be traveling to hurtle a cow 30feet (10metres) down a road?! Sounds stupid I know, but any help you...

If I shoot a bullet in the soft ground (meaning it doesn't bounce back), how is the momentum conserved? In that the entire Earth starts moving?

So, I am having a hard time getting started on this problem: Please help I have added the picture! By accident, a large plate is dropped and breaks into three pieces. The pieces fly apart parallel to the floor. As the plate falls, its momentum has only a vertical component and no component...

I need help understanding the principle of conservation of linear momentum here's the definition. priciple of conservation linear momentum is when there is no net external force (what does net external force mean?) acting on a system (what system?)of particles the total momentum of the...

55 kg swimmer is standing on a stationary 225 kg floating raft. The swimmer then runs off the raft horizontally with a velocity of +4.4 m/s relative to the shore. Find the recoil velocity that the raft would have if there were no friction and resistance due to the water. I used the equation...

I have been trying and trying to get this problem. I am using the fact that delta K = Fd, I set 0= to Fd of one part + Fd to the other part, and it is not the correct answer. In Figure 9-57, a stationary block explodes into two pieces L and R that slide across a frictionless floor and then...

Okay ya'll. I am back with mor eproblems I need help with. I had 18 problems, and I need some guidence on 6 of them. 1) A skier, of mass 60 kg, pushes off the top of a hill with an initial speed of 4.0 m/s. How fast will she be moving after dropping 10 m in elevation? I am...

Hi, I have tied to solve an exercise where I have kinetic energy and linear momentum and I have to calculate the speed and mass (not relativistic mass) I have these specifications: Wk = 5713.13 MeV P = 6584.92 Mev/c0 I have used these formulas: Wk = mc^2*((gamma)-1) P = (gamma)*m*v I...

Here's another one that it giving me a lot of trouble...althought it looks easy, i have tried eveything i could to solve it...but still doesn't give me the right answer... An explosion breaks an object into two pieces, one of which has 1.5 times the mass of the other. if 7500 J were released...

Two balls hit each other. One ball with a mass of 2m standing still relative to the earth. The other ball has a mass of 1m and hits the ball of 2m at a certain speed. The collision is elastic. Could you calculate the proportion of Linear Momentum between both balls after the collision with...

The height that a model rocket launched from Earth can reach can be estimated by assuming that the burn time is short compared to the total flight time, so for most of the flight the rocket is in free-fall. (This estimate neglects the burn time in calculations of both time and displacement). For...

Question: "The moon revolves around the Earth. Is the Moon's linear momentum p constant?(the p is supposed to be in italics and with an arrow over it pointing to the right. It's kinetic energy constant? Assume the orbit is circular." Being this a concept question and not a math question...

I feel pretty dumb, but I can't get the right answer. I'm terrible at basic math concepts, so don't ask me how I managed to get through 2 college math courses and now I'm stuck in physics AND statics. Anyway my problem is: 'Two astronauts (one mass 60 kg and one mass 80 kg) are initially at...

Hello again! I am having trouble with the following linear momentum problem: A has a mass mA = 9.11x10^31 kg B has a mass mB = 1.67x10^-27 kg They are attracted to each other by some electrical force. Say they are released from rest with a distance between them of Di = 3.0x10^-6 m...

I'm trying to do these problems by only reading about them in the book and, having not discussed them in class at all, I'm a little weary about some questions. So bear with me if some of the questions seem a little bit stupid .. I'm just starting out with this stuff. There are more questions...

The question I ask is linear momentum conserved in in instance cited below? You place a particle at the origin on a x-y axis and accelerate it to 61% of c in the y direction. Then you accelerate it to 61% of c in the x direction. The net velocity of the particle will be 86% of c at 45...