math mechanics questions

[Abdel Moniem]

a particle with constant accerleration along a straight line passing through points A,B and C with speed 2ms^-1 , 5ms^-1 and 8 ms^-1 respectively show that the ratio between the distances AB and BC is 7:13

 

[reachonlyme]

can u post the picture clearly?

 

[chishtyguy]

Your question isn't related to the question in the image... Can u plz post the year??

 

[reachonlyme]

Your question isn't related to the question in the image... Can u plz post the year??

Assalamu alaikkum...am atutor

 

[Abdel Moniem]

These are 2 separate question which I couldn't solve so may you help me to solve these 2problems

 

[chishtyguy]

Wa

Assalamu alaikkum...am atutor

Walaikum Assalam... Mashallah...

 

[reachonlyme]

These are 2 separate question which I couldn't solve so may you help me to solve these 2problems

yep..send the qns...inshlh..
better give the qn no in the book,

 

[Abdel Moniem]

The ratio question is question 12

 

[Abdel Moniem]

And here is the other question I'm stuck on

 

[chishtyguy]

a particle with constant accerleration along a straight line passing through points A,B and C with speed 2ms^-1 , 5ms^-1 and 8 ms^-1 respectively show that the ratio between the distances AB and BC is 7:13

Well to solve question no 1 sketch a graph... a straight line triangle would form.. with origin (0,0)
Acceleration is constant so... let time at A be (t), at B (X) and at C be ... so by using acceleration formula for instance to find time X; use (T-0)/(2-0) = (x-0)/(5-0)
U will get x=2.5 t , by using same thing u will get y= 4t
now using triangle formula find area OB=6.25t and OA= t
by subtraction find area AB and BC= 5.25:9.75
then u will get 7 : 13

 

[chishtyguy]

And here is the other question I'm stuck on

Can u give answer of this part so we can check...

 

[chishtyguy]

And here is the other question I'm stuck on

for part i time would be around 15 s... ii) time would be 30<T< 50 .... well for part iii) I can't see the speed but it will come by (60-0)/50-90= -3.5 ms^-1 .... It will 3.5 speed in opposite direction

 

[Abdel Moniem]

Part I and iii are incorrect

 

[Abdel Moniem]

I ) answer is 20seconds and iii) is 10m/s

 

[Abdel Moniem]

An electric train accelerates uniformly from rest to speed of 20ms-1 which it maintains until the brakes are applied it's them brought too rest by a uniform retardation equal in magnitude to twice its former acceleration . The total distance covered is 7.8 km and the total time taken is 7 minutes. Sketch a velocity-time diagram. Calculate 1)the time for which the train is traveling at constant speed. 2)the initial acceleration in ms^-2

 

[Abdel Moniem]

starting from rest at one set of traffic lights a car accelerates from rest to a velocity of 12m/s. It maintains this speed for 42 seconds until it decelerates to rest at the next set of red lights 60 seconds after leaving the first set. If the acceleration and deceleration are equal find the distance between the two set of lights?