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How long will it take for a truck to come to a full stop after going 25 m per s at an acceleration rate of -7.7 ms2 How long will an object take to fall 154 feet from an initial velocity of 0 m per s?
Fiendwyrm
the first question is rather simple to answer:
the truck is going at 25 meters per second and decelerating at 7.7 meter per second every second1 therefore after 1 second it will loose 7.7 MPS (meters per second) of speed. after 2 seconds it will loose 15.4 MPS. after 3.24 seconds, it will loose 25 MPS, coming to a full stop.
1("meters per second" is a speed measure, acceleration and deceleration is a change in speed and therefore we need to know the rate of change, i.e. how much speed (meters per second) it losses or gains every second. that is why we are using the term "meters per second every second")
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∙ 16y ago
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When an object is acceleraating its speed is?
Its speed is whatever the object is going at the time. Multiply acceleration by time and then add initial velocity.
Can an object's acceleration be a negative number?
Yes it can be.When a body has its initial velocity greater than its final velocity, then the body can have negative acceleration since acc.=change in velocity/time
Differentiate positive acceleration and negative acceleration?
A positive acceleration is a change in velocity such that the latter velocity is greater than the former velocity and is therefore going fasterwhile a negative acceleration or deceleration is a change in velocity such that the latter velocity is lesser than the former velocity and is therefore going slower.Now let us look at the equation of a uniform acceleration (the change in velocity is uniform):a = (vf-vi)/sIf the final velocity is greater, you will have a positive acceleration. If the initial velocity is greater, you will have a deceleration.
Can an object have a northward velocity and southward acceleration?
Yes, think about this; when you through a ball up in the air the velocity will be positive since its going up but the acceleration will be -9.8 since it is going against gravity.
How is the initial velocity zero but the acceleration is not?
Going back to definitions, Velocity is change of distance with time; and acceleration is change in velocity with time. Initially, the velocity is zero, as is the acceleration, BUT the Force of Gravity attracts the falling mass, and causes velocity to appear. But the continued application of the Force of Gravity causes the velocity to increase. And as we know, increase in velocity is acceleration. [space for QED]
What is the formula for acceleration?
a=dv/dt. By definition, acceleration is the rate of change of velocity. In mathematical notation, it is given as the formula stated above. Two special cases: 1. When acceleration is constant: The rate of change is a constant. Therefore, it can be calculated by: a=(vf - vi) / t where a is acceleration vf is final velocity vi is initial velocity and t is time taken 2. When velocity is constant: Velocity is not changing. The rate of change of velocity is zero. Acceleration has to be zero. * * * * * Note that velocity and acceleration are both VECTORS. Therefore, an object going round in a circle, at CONSTANT speed, has velocity and acceleration that are changing all the time - because the direction of motion is changing.
What is a moving object that has a velocity vector and acceleration vector in the same direction?
The net force is in the same direction as the acceleration of an object.
Which is greater an acceleration from 25kmh to 30kmh or an acceleration from 96kmh to 100kmh if both occur at the same time?
The acceleration from 25kmh to 30kmh is greater. Acceleration is the rate change in velocity with respect to time (dv/dt). Going from an initial velocity at one point in time to a final velocity at a later point in time, the average acceleration is given by (vf - vi)/(tf -ti), the change in velocity divided by the duration of acceleration. Since going from 25kmh to 30kmh is a change in velocity of 5kmh and going from 96kmh to 100kmh is a change in velocity of 4kmh, and the duration of each is the same, 25 to 30 is the greater acceleration.
How is velocity of zero different from an acceleration of zero?
Velocity basically means how fast you are going. Acceleration means how much your speed is increasing. So if there is zero velocity that means the object is not moving. If there is zero acceleration, that means that the speed is not increasing but there is actual speed and the object is not increasing it's speed what ever that may be.
What is the change in velocity divided by the time interval in which the change occured?
It is acceleration. The difference between final velocity and initial velocity, divided by the time is the AVERAGE acceleration. Remember, though that velocity is a vector. So if you are going round in a circle at a constant speed, your direction of motion is changing continuously and so you are always accelerating!
How do you know a moving object's acceleration?
Acceleration is the change in velocity. Velocity is the change in speed or direction. Therefore, acceleration is changing the change in speed or direction. So if you are going at 50mph and then you are going at 55mph and then at 60mph, your acceleration is constant at 5 mph. if the change in accleartion is changing, then it is not constant. If you turn dirctions even while you move at a constant velocity, you are accelerating.
What is an object that has velocity and acceleration vector going the same direction?
Moving in the positive direction at an increasing speed. (Accelerating positively)
