a bus is beginning to move with an accleration of 1 m/s^2. A boy who is 48m behind the bus starts running at 10m/s. after whattime will he be able to catch the bus?
a. 6s b. 8s c. 10

First you need to set up the equations of motion for the bus and the boy - do you know what they are?

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Originally Posted by ebaines

First you need to set up the equations of motion for the bus and the boy - do you know what they are?

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No I don't... plz help me

You need to memorize and know how to use the following equation, which gives the position of an object as a function of time depending on its initial position x_0, its initial velocity v_0, and its acceleration a:



For the boy to catch the bus you need to find the value for time when



What do you think the values of x_0, v_0, and a are for the bus and the boy? Clearly you have to decide whether you want to base this on either the starting point of the bus (i.e. set x_0 for the bus = 0 and x_0 for the boy = -48) or base it on the starting point of the boy (set x_0 = 0 for the boy and x_0 =+48 for the bus). It really doesn't matter which of these you choose; you just need to be consistent. So now set up the equation and solve for t. Hope this helps.