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Help! Specimen paper question

Hi can someone please explain how the answer to question 20 is C and not D. I can't seem to get 25m please help😣😣😣 ImageUploadedByStudent Room1465142641.675963.jpg

ImageUploadedByStudent Room1465142641.675963.jpg

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Reply 1

Alex Poole

The question is asking for the distance travelled in only the third second. Your calculations have worked out the distance travelled in three consecutive seconds, so you need to subtract the distance travelled in two seconds from that to get the distance travelled in just the third second.

45= 0*3 + 0.5*10*3^2
20=0*2 + 0.5*10*2^2

45-20=25

Reply 2

Smithenator5000

Original post by LittleBoxes

Hi can someone please explain how the answer to question 20 is C and not D. I can't seem to get 25m please help😣😣😣 ImageUploadedByStudent Room1465142641.675963.jpg

Posted from TSR Mobile

Hello there,

When faced with a question like this, I find it useful to draw a quick sketch of the velocity-time graph for this situation. This allows for me to easily visualise the nature of the question. Below, I have added an accurate plot (the sketch doesn't need to be this accurate, of course).