END of UNIT 3 QUESTIONS GRADE 11 Physics Part 10 alphaethiopianeducation

questions okay question number to get to school girl walks 1 North in 15 minutes okay terms distance she then works Southwest in 160 seconds with okay what is the girl's average velocity for her work to school for12 this for sou east and west fore spe withon in the and in the direction so which is unknown and so by using basic albra using the vector 4 opposite over hypoten by using here forus okay is ourant total dis fore spee speee total andal which is SX and S1 the same goes for and the vertical component is is for for component now we can use triang okay soare then for .82 second this will be the required answer okay question number nine very large magnitude of acceleration can be achieved in some devices such as in gun bullet in gun is accelerated from the firing chamber to the end of the barrel at an average rate of this 6.2 * 10 power of 3 m/s squ for 8.1 * 10 second2 * 6.2 * 10 Square for this second 10 * 8.1 * 10^ - 4 second okay what is the mule velocity that is it final vity spee 5.22 would be our required answer question number okay question number 10 it is very common for drivers when they enter the express rout Express rout they increase their speed while entering to the express rout on is Trav from adaba to Adama foree from from then at rate of 2.4 Square terms of 2.4 second Square for 12 seconds 2.4 of the situation situation are list the knows in this problem okay list the knows in this problem means these terms how far does the car travel in those 12 seconds distance what is the car's final velocity final the final for weoc we have 2.4 from this equation by using this formula question number 10 question number 11 okay question number 11 particle moving at 25 per second in strench line slows uniformly okay therefore we have the initial velocity met per second in strange line slows unation would be minus 2 m/s squ slow uniform okay look slows uniform at rate of 2 second every second 2 second over second which is 2 meus 2 in an interval of 10 second okay these are the Findation okay the final velocity final veloc the distance moved the distance mov every every two second every any for uni second would be our required answer this is the final aus for therefore again task 11 done task 12 task 12 at the instant the traffic light turns green okay automobile starts moving with constant acceleration of okay given spee fore at the same instant it work with constant speed of okay pass theile how far beyond the traffic signal will the automile overtake the track okay for Fore spe for foreign spee how fast will the automobile be at that instant okay okay final we can use this formula fore this 2.5 second fore fore okay either this one or this one spech okay for therefore the automobile overtakes the truck after okay question number 14 on it way along straight line car starts from okay so yeah we will have initial zero see then and accelerated at rate of 2.5 m/ squ for 10 second second Square second last second it maintained its speed for further 5 seconds and decelerated by 0.5 to come restus .5 then to okay what is the time taken for the entire motion okay did itav again the total distance then draw the position versus time and velocity versus time graph of the motion of the car motion graph spee total distance mean total time T12 T3 phe one pH pH T1 for fore for from fore spe from this one in terms of foree 2 so would be the total distance to find which is for spee for then for the acceleration part 2.5 question number 15 okay question number 15 on user manual of motor bike you see specification label the bike can accelerate to 100 km per hour from rest in 4 seconds what can you say about the maximum average acceleration of the bike how far does TR in this time okay therefore our initial hour speed what can you say about the maximum acceleration acceleration Max then how far does it travel okay from this acceleration 6.95 sare would be the required answer question number 15 then with question number okay the headquarter of Commercial Bank of Ethiopia is the tallest building in Ethiopia one of the top 10 tallest buildings in Africa top 10 tallest building if the engineer helmet is suddenly dropped from the proof during the final toing how long does it take for the helmet to reach the ground if someone needs to throw the helmet up to the top What minimum initial veloc is needed for can this inial be achieved by human being means ini can it be done by human then foreign spee spee it is Against Gravity against foree be at maximum it get okay spe human cannot reach to throw this Speed Up Against Gravity evenity so no would be our answer question number 16 can be done like this what question number stone strikes the ground with speed she stone strikes the ground with speed of second from what height was it released okay look released Force initial be released dropped okay from what height was it was released if the stone is thrown down with speed of 10 me second from the same height then what will be it speed just before hitting the ground okay fore foral GT then the final final okay Plus spe given okay fore so task 17 thenk okay question number 18 calculate the height of the building if it takes 4 second for ball to reach to the ground when it is thrown St up from the top of the building with an initial velocity of 8 m/ Second and sketch the motion diagram task 18 calculate the height the be height of the building if it takes 4 second for to reach to the ground when it is thrown straight up from the top of the building with an initial of second for initial of second we can use this formula because it's against gravity qu forance fore spee we can this form then motion question number 19 aaro can vertic jump over an object 2.5 high is given 2.5 then what is its initial vertical speed at Reach This height the initial velocity is asked okay how long will it stay in the air if if it jumping on ground height 2.5 Max maximum height finalx sooc we can use this formula V7 would be the initial speed spe this form for 7. which is 0.7 number question number 20 calate the magnitud of the acceleration of particle moving in circle of radius are 0.5 0.5 with constant speed of per second constant speed of per seconde answer question question1 question number 21 0.525 kg is attached 0.525 0.55 to 1.25 1.25 me and Swings in circular path making two Revolution per second okay our two reolution per second the angle of the string is nearly horizontal nearly nearly horizontal find the tension in the string okay Bing tension means the force the required term is tension force which is the cental means 2 2 * retion 2 second 2 * 2 4 second from this formula the force would be r52 the Rus 1.2 would be the tension force this is our required answer question number 21 and okay2 okay attached to 1.25 me ring Rus would be 1.25 and Swings in circular pass the angle of the Str away from the vertical is okay dire find the cental force acting on the ball and the speed of the ball okay for finding the Force therefore sin thet sin 30° opposite which is FC over hypotenuse 90° opposite which will be this one or for the tension this which foree 180 weight gravity for hypoten sin 30° TX then TX * Dee oppos which is TX over hypoten the same for this one then tus weal TUS which 66 3. so this will be our final answer the term so 2.69 question number which one of the following pairs of Concepts cannot both simultaneously be constant and non zero for body at the same time the answer will be Choice it implies there is change in velocity over time therefore velocity and acceleration cannot both be constant and non zero simultaneously for body and and body number two can an object can have variable speed but constant velocity explain and object because velocity is the speed of an object plus its direction if the speed of moving object varies if an object velocity is constant it means that both the speed and the direction of motion remain unchanged over time if the speed were to the velocity would also vary veloc incorporates both speed and variable speed implies variable velocity because includes speed as component therefore an object cannot have variable speed but constant okay question number three can an object can have constant speed but variable velocity explain yes it can it occurs when the object changes its direction of motion while maintaining constant speed if an object moves in curv or circular PA direction of motion changes even if speed remains constant example consider an object moving in circular path at constant speed it's is constantly changing because its direction of motion is continuously changing even though its speed Remains the Same question number four what do you mean by Motion in one and two Dimensions give examp examples of each type okay answer Motion in one dimension 1 in here the movement of an object along straight line where only one coordinate is considered it occurs when object travels along PA without changing it Direction Motion in one dimension without the changing direction which is straight lamp car moving along street road without changing lanes Motion in one di elevator moving up or down along vertical shaft compon okay Motion in two Dimensions or 2D the movement of an object in plane where two coordinates consider it occurs when the object move in both the horizontal and the vertical directions simultaneously so the horizontal the vertical at the same time motion from which moves both horizontally and vertically to the influence of gravity motion vertic motion an object rotating around fixed Point such as planet orbiting around star question number five can the displacement be greater than the distance traveled by an object give reason okay displacement answer no the displacement of an object can be either equal to or lat than the distance traveled by the object because displacement is vector which depends in number six can the direction of velocity of an object change while it acceleration is constant explain with example okay okay answer so the short answer would be yes this situation occurs in vertical motion vertic ball thrown vertically upward gravity 9.8 for example it can be free fall so it acceleration will be constant constant question number seven is it possible for body to be accelerated without speeding up or slowing down if so give an example okay answer yes it can acceleration therefore occurs whenever an object changes direction to speed up when the move car driving around round Bo is constantly accelerating even if its speed does not change okay question number3 describe the motion in each interval of the Velocity time graph shown in the figure below 1 2 3 four and which is to 10 we have uniform deceleration which is uniform acceleration in the opp which is uniform deceleration in the opposite fore welcome