can a body have a constant speed but varying velocity?give reasons?
65235
Do your own homework.
864717
-5ms-1. Speed and velocity are just different words for the same thing, and neither are dependent on direction.
792607
0 km/hr^2 .... because your speed doesn't change with time due to constant as you mentioned
1151625
newton's laws say you will keep moving at constant speed and direction.
912606
The simple answer is that the vector sum of the forces acting on an object must be zero if the object is to remain in "equilibrium" or in other words to have constant velocity.
1121031
yes, e.g. a braking car. \nOf course, you can't have accelaration and velocity going in opposite directions forever - the velocity will change to direction of acceleration eventually.
3944
The Trolley + Child being one single system, the speed of the Centre of Mass would not vary. It would remain the same velocity V.
557393
No. A mean is an average, so the only time the maximum velocity would equal the mean velocity is if the velocity was constant (unchanging).
947575
It is possible for an object to be falling fast enough for the force of air resistance to exceed the force of weight and for the object to accelerate upwards until it slows to a speed at which the force of gravity equals the air resistance and the net force equals zero.\nHowever, this will not happen on its own.  You cannot drop an object from a tall building and expect to see it accelerate up and down as it falls.  As the object accelerates downward, its velocity increases, causing the force of air resistance to increase (meanwhile weight stays constant).  The object will approach an equilibrium point at which the air resistance equals the weight and the new force equals zero (speed at this point is called its "terminal velocity").  At this point, the object stops accelerating and travels at a constant velocity until the equilibrium is disturbed.  The object cannot cross this equilibrium point on its own...but for example, if you shot a bullet straight down out of a gun, the bullet might exit the gun barrel at a speed such that the drag force is greater than the weight, and the bullet slows down as it falls, approaching the equilibrium point.
730176
All of these questions can be answered using Newton's 2nd Law:\n\n"The rate of change of momentum of a body is proportional to the resultant force acting on the body and is in the same direction."\n\nThus, if a box has a net force of 0 N, it will not accelerate. This means that its velocity will not change. Note that this DOES NOT necessarily mean that its velocity is 0, just that the velocity is not changing.\n\nIf the box has a net force of 15 N, then it will accelerate in the direction of the applied force. Note that the magnitude of the acceleration is dependant upon the mass of the box.\n\nSo, to answer your two questions:\n\nA) Yes, it will have constant velocity.\n\nB) Yes, the box will accelerate.
288257
No force is needed to maintain motion.  You need a force to change motion: speed up, slow down, or change direction.
1103152
Falling objects do not fall at a constant speed, they accelerate (get faster) the longer they fall. In a vacuum (no air resistance) two objects of the same mass (weight) experience the same acceleration. So if they're dropped from the same height, they will hit the ground at the same time. \n\nIn the atmosphere, air resistance will diminish the force of gravity, so two objects of different shape or density would accelerate at different rates because of different air resistance.
124905
There is no absolute reference frame, that is, there is no universal "stationary point" that we can use to say whether an object is moving.  Thus, every object is "at rest" in the frame of reference centered on itself.  In that frame of reference, an object's mass is always the same, its so-called rest mass.  That is the mass that you are likely thinking of when you say it doesn't increase.\n\nHowever, if the object is moving at a high speed relative to an observer, its mass is increased in the reference frame of that observer.  It will require more force to accelerate it a given amount, etc.
279138
There can be two reasons:\n\n1.  There is an external force acting on the object.  If the force has a component in the direction of the motion, it would speed up in the direction; if the force has a component against the direction of motion, the object would slow down in the direction of motion.\n\n2.  The frame from which you are viewing the object is declerating or accelerating.  Accordingly, there would be a pseudo force acting on the body, making it seem to decelerate (slow down) or accelerate.
313900
Think of this\nwhen it comes to space the constant thing is the speed of light. Speed is the TIME it takes something to travel set distance.\nAt the moment we are moving through space. An hour ago we were a few hundred thousand miles from where we are now. If you were sitting still where we were a few hous ago, you would be slightly older than us.\nThis is because the constant thing in space is the speed of light. As we get closer to the speed of light either time gets smaller or distance gets smaller.\n\nIf this does not seem possible, just think of a unit of time as one vibration of an atom. Go faster, atoms vibrates slower, your time is therefore slower than some one who is still. (this is a metaphor people can comprehend, not quantum fact)\n\nSo question 1. Light is travelling at speed of light. Time and space do whatever they have to do to accomodate this.\n\nQ2 No, see Q1. You also would no be strong enough to throw the ball\n\nQ3. The closer one gets there first. just like anything else.\n\nQ4. What fuel? It would accelerate exponentially as the mass decreased. Top speed comes dowon to rates of accelerate, motor efficiency, drag, ect. Then as you got really fast your mass increases. Mass increases (again I'll use a compehendable metaphor and not quantum physics) because distance decreases, things are closer together, denser, heavier. Then your rate of fuel consumption would increase exponetially and your velocity would barely change. Then you'd run out of fuel
55228
Not always. If the object is in motion, then no. The total energy, aka total mechanical energy is always constant due to the Law of Conservation and Energy. It depends on the problem. Certainly,if you know the total mechanical energy in the system than you can find a variable for the kinetic energy or gravitational potential energy,assuming you given other variables.
848599
No. The velocity of the wheel is changing as the car moves (because velocity indicates direction). So as the car moves forward, the velocity of the surface of the wheel is continuously changing.