3 physics questions

Q16 is easy too

minimum travel time = $$\frac{1hr}{65miles}\times \frac{455miles}{1}=7hours$$

9.5-7=2.5hours

So you have less than 2.5 hours for lunch.

question 13

These are the motion in one direction formulas

You have initial and end velocities and distance and you want accel

You have u,v and s and you want a

no 4 is the only one that doesn't need time so use that one.

$$\\0=40^2+2*a*200\\
0=1600+400a\\
0=4+a\\
a=-4$$

Acceleeration    $$-4m/s^2$$

But you are just asked forthe magnitude - that is like absolute value - so the answer is 

$$4m/s^2$$

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14 is east

The cat goes 15m+10m=25m

in 20sec+8sec=28sec

average speed = 25/28=0.893m/s

very nice .. 

thank you melody