So, a jet moving with a constant velocity at 800 miles per hour along a straight line has zero acceleration, even though the jet is moving really fast, since the velocity isn’t changing.

Motion with Constant Velocity: When an object is moving with constant velocity, it does not change direction nor speed and therefore is represented as a straight line when graphed as distance over time. You can also obtain an object’s velocity if you know its trace over time.

If an object is changing its velocity -whether by a constant amount or a varying amount – then it is an accelerating object. And an object with a constant velocity is not accelerating.

Velocity is the rate of change of position with respect to time, whereas acceleration is the rate of change of velocity. Both are vector quantities (and so also have a specified direction), but the units of velocity are meters per second while the units of acceleration are meters per second squared.

Velocity is directly proportional to time when acceleration is constant (v ∝ t). Displacement is proportional to time squared when acceleration is constant (∆s ∝ t2).

Unit of acceleration is the metre per second per second (m/s2). Definition. The snewton is that force which, when acting on a mass of one kilogramme, produces an acceleration of one metre per second per second.

Although you are in fact speeding up, increasing your velocity, the rate at which you are speeding up has reduced. Ie acceleration has reduced. Because acceleration is still positive your velocity is increasing but the magnitude of that acceleration is decreasing.

Likewise, as long as acceleration is negative, velocity decreases even if acceleration is increasing. Acceleration is the rate of change of velocity defined by a=dv/dt, so even if acceleration is decreasing as long as it is positive it velocity would increase.

In an inverse relationship, when one variable increases, the other variable decreases. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force.

Acceleration is the change in velocity per unit time. So when acceleration is zero, there is no change in velocity i.e,velocity is constant.

Acceleration has a different story. At the middle (x = 0), acceleration is zero. At the extreme ends, when a spring is at its maximum stretch or compress, the spring force is at its maximum magnitude, and therefore the acceleration it gives to the attached mass is maximum.

Zero velocity is essentially no movement. What this means is that your change in position from time a to time b is zero. This happens when you throw an object to the sky. Just before it falls, when there is no force moving it upwards, it will remain motionless and its velocity will be zero.

Why does acceleration is zero when velocity is maximum in SHM? Acceleration is zero because at that point, it is the mean position, which means it is the equilibrium position. Hence, the spring is not compressed (or extended) or the pendulum suffers no tangential force.

If acceleration is positive to the left and negative to the right, the point is a maximum velocity. In the example, a=3cos(t) is positive just before t=π /2 and negative just after, so it is a maximum; however, 3π/2 is a minimum because a=3cos(t) is negative just before 3π/2 and positive just after.

When the velocity is minimum, the acceleration could be anything, really. If you throw a ball vertically up into the air, the acceleration will be approximately 9.8m/s/s throughout the entire flight. The ball will slow down its velocity (decelerate at 9.8m/s/s) until it reaches the top of its flight.

So, when velocity is maximum, acceleration is minimum (zero).

Hence, the minimum acceleration should be gμ. So, the correct answer is option A i.e. gμ. Note: Friction force can never be greater than the applied force. The direction of force and friction force are always in opposite directions.

The velocity of a body is maximum means that you can not increase it further. Means change in velocity is zero. Means change in velocity is zero. Hence acceleration is zero.

The maximum speed is called terminal velocity. The terminal velocity speed changes depending on the weight of the object falling, its surface area and what it’s falling through. So its terminal velocity speed is much slower than a rock with the same weight.

time. The time is the time in the middle of that interval (if that makes sense). This shows Usain with an average speed of 5.38 m/s at a time of 0.91 seconds and 9.83 m/s at 2.35 seconds. From this, I can calculate the average acceleration (during this interval) to get a value of 3.09 m/s2.

We’ve seen humans experience, for a very brief period of time, as much as 40 Gs acceleration, which is 40 times the force of gravity—and they’ve survived. Colonel John Stapp’s amazing self-experiments in the 1960s on rocket sleds are worth noting here.

Usain Bolt

If you can hold it for a marathon (42,2km), you can run a 1hr 26 min marathon. The mile, 1/4mile, and 100m times are all impressively fast and physiologically possible. The marathon time is completely unrealistic. I would say 17 miles per hour is very fast (way above average) for any age group.

Average speed – indications Most cyclists can achieve 10-12 mph average very quickly with limited training. Reasonable experience, medium (say 40 miles): average around 16-19 mph. Quite competent club rider, some regular training likely, medium-long distances (say 50-60 miles): 20-24 mph.

But, by most standards, running at 12 mph isn’t all that fast. It means an average of a 1:15 for a quarter mile, which is really the longest sprint (maybe 800 can be considered a sprint). 37.5 for a 200.

Speed. If you can still run comfortably at that speed, turn it up another notch. Your maximum sprinting speed is likely to fall between 8 and 12 mph.