1. The diagram below shows the motion oF an object on a Flat surface. The object moves at Constant Speed. Circle the parts of the path where the object is accelerating (change in motion]. 2. The diagram below shows the motion of an object on a Flat surface. The Object moves at Constant Speed. At what point on the path below will the acceleration (change in motion] be a} the largest? b] the smallest (non-zero) ? 3. Read the following: Estimating Uncertainties. For a table-top measurement of length, uncertainty is mainly due to reading the scale at both ends. The scale can be read to 0.25 mm at each end, so we take the scale reading uncertainty to be + 0.5 mm. In the case of the measurement of radius of the platform however, we have some extra uncertainty due to a) the fact that we have to estimate the middle of the central pin and the centre of the accelerometer (1 1 mm) b) the fact that we need to hold the ruler up above the platform to measure the radius and this requires some judgement of level and some parallax in reading the accelerometer which lies some distance behind the scale (about + 2 mm for both effects) So the total uncertainty in radius is about + 3.5 mm. For a measurement of time on the photogate, the main source of uncertainty is the precision of the photogate which is 1%%. So the uncertainty is 1% of the reading. (ie. 0.01 x reading) For a measurement of acceleration on the sensor, the main source of uncertainty is the fact that the reading changes over time due to platform bearing friction. We will use the mean value for the reading and the 'standard deviation' as the uncertainty. Both of these values will be generated by the software. 4. Fill in total uncertainties in the data chart (pg 63) for this lab. 5. Read the following: Calculating Uncertainties. To find a percent uncertainty, divide the uncertainty by the value and then convert to percent. Express to 2 sig fig. uncertainty value x 100 %% So if we have a distance reading of 520 + 10 mm, the percent uncertainty is: 10 520 x 100 % = 1.9% To find the uncertainties in quantities we calculate, we use the following simple rules (which are derived using calculus) i) if you multiply or divide numbers, add the percent uncertainty. ex: v= 2ar/T Since we divide radius by time , we add the percent uncertainty in radius to the percent uncertainty in time to get the percent uncertainty in