A. correct as it is
B. 5, 4, 3, 0
877.71=877.7
when rounding, look at the previous place value to determine if you should round up or down :)
Answer:
(a) 
(b) 
(c) 
Step-by-step explanation:

(a) when t = 44sec

s(44) ≅ 
(b) How fast the hammer is traveling i.e. the speed of the hammer.
To find speed, we differentiate the distance s(t) with respect to time, t

at t = 44sec,

≅ 
(c) The hammer's acceleration can be obtained by differentiating the speed v(t) with respect to time, t

There's no need to substitute t = 44sec because the acceleration is independent of time.
4 hours. You divide 240 by 60 because you travel 240 total miles and you 60 mph and you will get 4 and it will be 4 hours