To measure g by use of a millisecond timer In this experiment the time taken by a brass ball to fall through a measured height is found by means of an electric clock which measures time intervals in thousandths of a second or milliseconds (ms). This works on a different principle from an ordinary electric clock. It generates electric […]
Distance moved by a freely falling body related to time of fall The value of the constant here is equal to t g and we can best illustrate the relationship between distance fallen and time taken by plotting a graph of x against t2. We should expect to obtain a straight line through the origin, the gradient […]
To study the simple pendulum. Measurement of 9 For experimental purposes, a simple pendulum is made by attaching a length of thread to a small brass or lead sphere called the bob. The thread is held firmly between two small pieces of wood (or a split cork) held by a clamp and stand. One complete to and fro […]
The simple pendulum A story is told of Galileo, that he was once attending a service in the cathedral at Pisa when his attention was distracted by the swinging of a lamp which was suspended from the roof by a long chain. Using the beats of his pulse as a clock, he noticed that the time of swing […]
Galileo Galilei The equations of motion explained earlier in this chapter were first worked out by Galileo Galilei, who was born at Pisa in Italy in 1564. Galileo began his university career as a medical student, but later forsook medicine for the study of mathematics and physics. His outstanding ability earned him a lectureship by the time he […]
Acceleration from velocity-time graph By a process of reasoning similar to that used in the section above relating to the distance-time graphs, it may be shown that, A stone is thrown vertically upwards with an initial velocity of 14 m/s. Neglecting air resistance, find: (a) the maximum height reached; (b) the time taken before it reaches the ground. […]
Velocity from distance-time graph When a body moves with uniform velocity it will travel equal distances in equal intervals of time, and so a graph of distance against time will be a straight line (Fig. 3.3 (a)). Now if we take any point A, on the graph and drop a perpendicular AB on to the time axis, […]
Uniformly accelerated motion represented graphically Fig. 3.2 shows the velocity-time graph for a body which starts with a velocity of 3 m/s and moves with an acceleration of 2 m/s 2 for 4 s. In this case the velocity increases uniformly, and therefore the average velocity is equal to the velocity at half time and is represented […]
Velocity-time graphs The distance covered in 5 s by a body moving with a velocity of 6 m/s is given by, Distance = velocity x time = 6 x 5 = 30 m If we plot a graph of velocity against time for this case a straight-line parallel to the time axis is obtained (Fig. 3.1). […]
Equations of uniformly accelerated motion First equation of motion. Suppose a body which is already moving with a velocity of u in ml begins to accelerate at the rate of a in m/s2. The velocity will now nicer -, by the numerical value of a in m/s for each second that it moves. The increase velocity in […]