#### To investigate the relationship between Angular Acceleration and Torque.

Circular Motion Practical - UB Physics Assessment 1 Aim: To investigate the relationship between Angular Acceleration and Torque. Hypothesis: Angular Acceleration will be proportional to torque ( ??????) according to the equation ????I? Independent Variable: ????Torque : Torque was changed by varying both F and r in the formula ????Fr . Force is varied by changing the hanging mass and therefore the force due to gravity. The radius (r) is varied by using different drive radii (shown in the method diagram), ie. applying the force due to gravity to the different sized rims underneath the cylinder being accelerated. Dependant Variable: ????Angular Acceleration : A cylinder on a low friction axle is accelerated by the independent variable - torque. The measurements taken are the velocity at the rim and the diameter of the cylinder (to find r). Variables to be controlled: -Radius of velocity measurement. The radius from the centre of rotation to the rim which the ticker tape was attached to was a constant 0.124m. Velocity measurements derived from the ticker tape therefore exist at this radius, so it is used to calculate angular velocity ?=v/r. -Radius of torque application. The radius from the centre of rotation to the rim which the force was applied to was varied between three values, 0.0153m, 0.0252m, and 0.0352m. These values are used calculate torque ?=Fr

#### length of a simple pendulum affects the time

. Plan Aim To investigate how the length of a simple pendulum affects the time for a complete swing. Variables length The length of the pendulum has a large effect on the time for a complete swing. As the pendulum gets longer the time increases. size of swing Surprisingly, the size of the swing does not have much effect on the time per swing. mass The mass of the pendulum also does not affect the time. air resistance With a small pendulum bob there is very little air resistance. This can easily be seen because it takes a long time for the pendulum to stop swinging, so only a small amount of energy is lost on each swing. A large and light pendulum bob would be affected by a significant amount of air resistance. This might change the way the pendulum moves. gravity The pendulum is moved by the force of gravity pulling on it. On the Moon, where the pull of gravity is less, I would expect the time for each swing to be longer. Theory When the pendulum is at the top of its swing it is momentarily stationary. It has zero kinetic energy and maximum gravitational potential energy. As the pendulum falls the potential energy is transferred to kinetic energy. The speed increases as the pendulum falls and reaches a maximum at the bottom of the swing. Here the speed and kinetic energy are a maximum, and the potential energy is a minimum. As the pendulum rises the

#### How the length of string affects one oscillation of a pendulum.

Physics Coursework: How the length of string affects one oscillation of a pendulum By Will Rudd How the length of string affects one oscillation of a pendulum Plan: In my investigation I will try to find out what affects the oscillation of a pendulum, I will try to quickly and simply work out what could actually be a variable. I already know that the period (the time taken for the pendulum to swing there and back) is the dependent variable, meaning that it's dependant on the other variables, the only possible variables are: * Weight/mass of the pendulum, * Distance that the pendulum is pulled back and * Length of the string To find out which of these variables could effect the period I carried out a short series of preliminary tests. Weight/Mass: For the weight/mass, the distance pulled back is 30cm and too keep the constant the string must remain the same length, hence the only variable that I changed was the weight by adding 50g, making sure this is a fair test. I allowed the pendulum to oscillate 10 times and then divided the time by 10 to work out the average oscillation time, I repeated each test twice and then worked out the average. These were my results: Mass (in grams) Time taken for ten periods/oscillations (in seconds) Test 1 Test 2 Average 50 4.38 4.37 4.375 00 4.32 4.58 4.450 50 4.06 4.40 4.230 From this test just

#### Terminal Velocity Investigation.

Terminal Velocity Apparatus: A 100cm ruler A bun case - (to represent the parachute) A clamp and stand A stopwatch Method: The clamp and stand was set up at the edge of the table. The distance from the floor to the top of the table was measured and recorded. The 100cm ruler was then secured to the clamp - so the 0cm mark was touching the top of the table. It was important to make sure that both these factors were measured accurately in order to perform a fair test. It was then possible to identify the distance of the fall. Several heights were determined from 0.40m to 1.60m. A bun case was held at the first height and then released (so it could fall to the floor). The time taken for the bun case to reach the floor was recorded using the stopwatch. This was repeated three times for each height, to make it a fair test, allowing room for human error. It was then possible to work out an average for that particular height ((time 1 + time 2 + time 3) ÷ 3). This process was reiterated for each of the nine heights and a table of results was created. Results: Height (m) Time in secs. (1) Time in secs. (2) Time in secs. (3) Average time 0.40 0.79 0.73 0.82 0.78 0.50 0.87 0.95 0.90 0.91 0.60 0.87 0.99 .07 0.98 0.80 .00 .02 .09 .04 .00 .17 .16 .12 .15 .20 .28 .31 .28 .29 .40 .36 .40 .32 .36 .50 .49 .56 .30 .45 .60 .56

#### An Investigation To Find Out What Affects The Stopping Distance Of A Toy Car.

An Investigation To Find Out What Affects The Stopping Distance Of A Toy Car Introduction: We are going to investigate how changing the height of the starting position of the car of the ramp affects the stopping distance of the toy car. Variables: Things we could change to affect the stopping distance - * Gradient of ramp * Speed * Counter forces * Mass of car * Starting position of car on ramp Dependant Variable: We will investigate a change in the starting position of the car on the ramp. Apparatus: * A ramp * A toy car * 3 or 4 metre rulers (depending on the distance the car travels) * Clamp stand (to support the ramp) Fair Test: To make our test fair there are several things that we will have to keep the same: * The same toy car must be used each time * The ramp must stay at the same height * The same ramp must be used * The distance must be measured in the same units (e.g. cm) Diagram: Safety: In an experiment like this there aren't many safety precautions to take as nothing dangerous is being used but the ramps could easily be tripped over and cause injuries - to ensure this doesn't happen people must act sensibly. Method: * Set up the apparatus as it is show in the diagram * Make sure the ramp is marked at every 10cm from the bottom of the ramp * Start the toy car from behind the 10cm mark on the ramp, let it roll down the ramp and

#### The Study Of the Motion Of A Falling Cake Case With Reference To Terminal Velocity

The Study Of the Motion Of A Falling Cake Case With Reference To Terminal Velocity Introduction: I am going to study and analyse the motion of a falling cake case with reference to Terminal Velocity. What is Terminal Velocity? Terminal Velocity is the maximum speed attained by a falling object. And to find the terminal velocity of my falling cake cases I will use the equation Speed = Distance Time Method I have devised a fair test to study the motion of a falling cake case. I will be using the following equipment to carry out my experiment. - 2 x 1 metre rulers - Stopwatch - 5 cake cases - Stand - Clamp Clamp 20cm Eye level Stand 180cm Bench Top Will I have a fair Test? To ensure that I am carrying out a fair test I have taken some steps to do so. Firstly I made sure that all the cake cases are all the same size and shape I will vary two factors in my experiment - Drop height - Weight of the cake case Every other factor in my experiment will remain the same (constant) How will I collect my Data Drop Height Time 1 (In sec) Time 2 (In sec) Time 3 (In sec) Average Time (In sec) Terminal Velocity (m/s) 80 cm 50 cm 20 cm 90 cm 60 cm 30 cm I will enter all my readings into a number of tables such as the one above. After collecting all of my data, I will set it out on a graph putting the drop height against the time. I have

#### Investigating the amazingness of theBouncing Ball!

Physics A2 Coursework Investigating the amazingness of the Bouncing Ball! In this investigation I will lead you through my experiments and findings on the decaying bounce of balls. From this investigation I want to have worked out the effect of temperature change on the decaying bounce of a ball. However, at first I will have to choose suitable variables for this experiment. First of all I had to distinguish a method for measuring the heights reached by the bouncing ball. My initial idea was to have a white ball bounce against the backing of a grided black board, so as the ball bounced I'd mark out where the ball bounces. Using a light gate the second time, I'd make sure that the ball did indeed reach that point. However, the ball wouldn't bounce to the exact same height every time, as the ball may bounce sideways and so the height reached would change. Where I mark out the height depends on my eye level and how quick I am to mark out this height may be delayed by i.e./ how tired I am at the time. This method is very prone to error. Another method that may have worked would be to have metal claws, interlocking however not making contact ie. like a grid, but with a charge running through them. A metal or a ball wrapped with tin foil or just a thin layer of metal on the outside of a ball would be bounced onto this grid. Each time the metal plated ball bounces

#### Planning experimental procedures

Skill Area P: Planning experimental procedures Introduction A trolley is pushed to the top of a ramp, the summit being 20cm from the ground, and then is released. It rolls all the way down the ramp, of 2 metres, before it collides with the wall at the bottom. A couple of keen scientists thought it would be interesting to record the time taken for the trolley to reach the bottom and then calculate its average speed. They let the trolley fall down the ramp two more times after that, just to make their results more accurate. They also wanted to investigate if the height of the summit made any difference to the average speed, so they raised the ramp to 30cm and pushed the trolley down the ramp again and recorded the time. Basically I have been asked to act as the two enthusiastic experts and test, as a primary objective, to see if the height of the summit affects the average speed at which the trolley travels down the ramp. Based on my existing scientific knowledge, I know that this experiment depends on a certain type of energy being converted into another type. When the trolley is raised to the top of the ramp, it gains a certain amount of potential energy - this is converted into kinetic (movement) energy as the trolley moves down the slope. Too see what factors may affect the way the experiment turns out, it may be useful to look at the formula for potential energy. P.E

#### Gears Introduction

Gears Introduction Gears are very versatile and can help produce a range of movements that can be used to control the speed of the action. In basic terms, gears are comparable to continuously applied levers, as one tooth is engaging, and another is disengaging. The gear wheel being turned is called the Input gear and the one it drives is called the Output gear. Gears with unequal numbers of teeth alter the speed between the input and out put. This is referred to as the Gear Ratio. CALCULATING RATIOS The following example shows how the ratios are calculated. If the input gear (A) has 10 teeth and the output gear (B) 30 teeth, then the ratio is written down as 3:1 Ratio = number of teeth on the output gear B (30) number of teeth on the input gear A (10) Therefore the ratio is written down as 3:1 The first figure (3) refers to how many turns the input gear (1) must turn in order to rotate the out put gear 1 full revolution. Simply divide the amount of teeth from the input by the output gear to work out the ratio. The principle behind gears is also very simple. In the above example, for every complete revolution of the input gear the out put turns 1/3 of the way round. This means you are slowing down the action and are referred to in engineering terms as "Stepping Down". If we reverse everything then the opposite happens and we "Step Up". It takes 1 turn of the

#### How does the weight of a pendulum effect its oscillation time.

How does the weight of a pendulum effect its oscillation time Plan The key factors that could affect this experiment are that the length of pendulum varying will change how far it has to swing to complete an oscillation. The weight of the pendulum will have a effect on the oscillation time because the pendulum will have more weights which will increase the surface area for air resistance to take place this is the only possible way the weight of the pendulum will affect the oscillation time because, gravity is a standard force, so the weight will not effect the amount of gravity taking place. The angle at which it is dropped at is another key factor because, if it is dropped from higher up it has longer to pick up speed so therefore it shall travel higher up giving it a longer oscillation time. If the pendulum is dropped from a lower then it shall have less time to pick up speed and so will not travel as high up on the other side. The force at which it is released, if the pendulum is pushed it shall have gained more speed than if it was just released because it started with more momentum. Before we carried out the experiment we did some preliminary work testing by how much we should increase the weight each time, we also tested different lengths of string to see which was most effective. We decided to increase the weight by 100g each time so we timed the weight of the