# Speed velocity and acceleration

## Uniform acceleration

Uniform acceleration A. body is said to move with uniform acceleration if its rate of change of velocity with ttme is constant. Example. A motor car is uniformly retarded and brought to rest from a speed of 108 m h in 15 s. Find its acceleration. therefore 108 x 1000 108 krn/h = 60 x 60 = 30 m/s initial …

## Uniform velocity

Uniform velocity A. body is said to move with uniform velocity if its rate of change of distance moved vith time in a specified direction is constant) Acceleration When the velocity of a body is changing, the body is said to be accelerating. celebration is defined as the rate of change of velocity with time. laceration is regarded …

## Displacement is defined as distance moved in a specified direction.

Displacement is defined as distance moved in a specified direction. In ordinary conversation the word “velocity” is often used in place of speed. In science, however, it is important to distinguish between these two terms. Velocity is defined as the rate of change of distance moved with time in a specified direction (or, rate of change of displacement). …

## Distance and displacement

Distance and displacement We have just explained the difference between scalar and vector quantities. Now, if we say that a motor-car travels a distance of 100 m, the expression- “100 m” is a scalar quantity. But if the car happens to be moving along a straight line and we mention the direction of travel, e.g., 100 m due …

## Scalar and vector quantities

Scalar and vector quantities Most quantities measured in science are classed as either scalar or vector quantities. A scalar quantity is one which has magnitude (or size) only. A vector quantity is one which has direction as well as magnitude. Thus when we say that a library contains 2000 books or a fuel tank contains 50 liters of …

## Actual speed

Actual speed Normally, a driver notes his actual speed at any moment by glancing at the speedometer, but for reasons which we shall not discuss here, speedometer readings are not particularly reliable. In order to obtain an accurate value for the speed of a vehicle at any instant it would be necessary to measure the distance moved in …

## Speed velocity and acceleration

Speed velocity and acceleration Average speed Unless he is travelling on a motorway, a motorist cannot usually maintain a constant speed for any length of time. In the ordinary way, traffic conditions frequently cause him to change speed or stop. When deciding the time to allow for a particular journey, the motorist must therefore have some idea of …