Physics Homework help!?

Question

Assume a parcel of air in a straight tube moves with a constant acceleration of -5 m/s2 and has a velocity of 10.0 m/s at 10:05:00 a.m. on a certain date.

(a) What is its velocity at 10:05:01 a.m.?

v = 5.00 m/s

(b) What is its velocity at 10:05:02 a.m.?

v = wrong check mark

Your answer differs from the correct answer by orders of magnitude. ???? m/s

(c) What is its velocity at 10:05:02.5 a.m.?

v = ???? m/s

(d) What is its velocity at 10:05:04 a.m.?

v = ???? m/s

(e) What is its velocity at 10:04:59 a.m.?

v = ???? m/s

please tell me how you do it also

Answer 1

With an acceleration of -5 m/s2 - it obviously slowing down.

You will need to use the equation v = u + at

a) after 1 second v = 10 - (5 x 1) = 5 m/s

b) after 2 seconds v = 10 - (5 x 2) = 0

c) after 2.5 s v = 10 - (5 x 2.5) = -2.5 m/s ( ie travelling in the opposite direction

d) afetr 4 s v = 10 - (5 x 4) = -10m/s

e) 1 second before the start v = 10 -(-5 x1) = 10 + (5x1) = 15 m/s