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***** Basic Physics Homework *****

PLEEZ HELP!!!!! these are due at 8. i got transfered to this new school and they are much farther ahead of us in the curriclulum please HELP ME :(

ANY ANSWERS ARE GREATLY APPRECIATED :D :D :D

#4 PART 1

Two cars travel in the same direction along a

straight highway, one at a constant speed of

55 mi/h and the other at 66 mi/h.

Assuming they start at the same point, how

much sooner does the faster car arrive at a

destination 10 mi away? Answer in units of

min.

Answer =1.81 min

#4 PART 2

How far must the faster car travel before it

has a 13 min lead on the slower car? Answer

in units of mi.

#6

A tennis ball with a speed of 8 m/s is thrown

perpendicularly at a wall. After striking the

wall, the ball rebounds in the opposite direc-

tion with a speed of 7 m/s.

If the ball is in contact with the wall for

0.012 s, what is the average acceleration of

the ball while it is in contact with the wall?

Answer in units of m/s2.

#7

A subway train starting from rest leaves a

station with a constant acceleration. At the

end of 9.27 s, it is moving at 22.6188 m/s.

What is the train’s displacement in the first

6.29433 s of motion? Answer in units of m.

#8

Highway safety engineers build soft barriers

so that cars hitting them will slow down at a

safe rate. A person wearing a safety belt can

withstand an acceleration of 300 m/s2.

How thick should barriers be to safely stop

a car that hits the barriers at 89.4 km/h?

Answer in units of m.

#9

Two particles are at the same point at the

same time, moving in the same direction. Par-

ticle A has an initial velocity of 7.9 m/s and

an acceleration of 2.8 m/s2. Particle B has an

initial velocity of 2.9 m/s and an acceleration

of 5.2 m/s2.

At what time will B pass A? Answer in

units of s.