Ace your Physics preparations for Motion with us and master General Science for your exams. Learn today! It is a vector quantity. Scalar quantities : The physical quantities which have only magnitude and no direction are called scalar quantities or scalars. Examples: Mass, volume, density, time, temperature, electric current, Luminious intensity, etc. Vector quantities : The physical quantities which have both magnitude and direction and obey the laws of vector addition are called vector quantities or vectors.
Examples Displacement, velocity, acceleration , force, momentum, Impulse, etc. So option 1 is correct. Get Started for Free Download App. More Motion Questions Q1. The inability of a body to change its state of rest or uniform motion by itself is known as :. A body of 20 kg is lying at rest. The statement of Newton's second law states. An object with a mass of g is moving in a circular orbit with a radius of 2. The correct expression for the centripetal acceleration ac is.
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. The data tables below depict motions of objects with a constant acceleration and a changing acceleration.
Note that each object has a changing velocity. A falling object for instance usually accelerates as it falls. Our free-falling object would be constantly accelerating. Given these average velocity values during each consecutive 1-second time interval, we could say that the object would fall 5 meters in the first second, 15 meters in the second second for a total distance of 20 meters , 25 meters in the third second for a total distance of 45 meters , 35 meters in the fourth second for a total distance of 80 meters after four seconds.
These numbers are summarized in the table below. This discussion illustrates that a free-falling object that is accelerating at a constant rate will cover different distances in each consecutive second.
Further analysis of the first and last columns of the data above reveal that there is a square relationship between the total distance traveled and the time of travel for an object starting from rest and moving with a constant acceleration. The total distance traveled is directly proportional to the square of the time.
For objects with a constant acceleration, the distance of travel is directly proportional to the square of the time of travel. The average acceleration a of any object over a given interval of time t can be calculated using the equation.
This equation can be used to calculate the acceleration of the object whose motion is depicted by the velocity-time data table above. The calculation is shown below. Typical acceleration units include the following:. These units may seem a little awkward to a beginning physics student. Yet they are very reasonable units when you begin to consider the definition and equation for acceleration. The reason for the units becomes obvious upon examination of the acceleration equation.
Since acceleration is a vector quantity , it has a direction associated with it. The direction of the acceleration vector depends on two things:. The general principle for determining the acceleation is:. This general principle can be applied to determine whether the sign of the acceleration of an object is positive or negative, right or left, up or down, etc. Consider the two data tables below. The basis for this is a This incident and others have When this sensor is attached to a neck, it can precisely recognize voice through vibration of the neck skin and is not According to the National Weather Service, doing so could actually Have We Detected Dark Energy?
Scientists Say It's a Possibility. Their models could help researchers develop and test But a new study finds that water bears propel themselves through sediment and soil on eight stubby legs, in The researchers measured the spontaneous emission of fast Now they're building the hardware for Hidden Behavior of Supercapacitor Materials Nov.
0コメント