A time-varying horizontal force F(t) = At4 + Bt2 acts for 0.500 s ...

[tiffannnnyyyyyy]

A time-varying horizontal force F(t) = At4 + Bt2 acts for 0.500 s on a 12.25-kg object, starting at time t = 1.00 s.
 
  In the SI system, A has the numerical value 4.50 and B has the numerical value 8.75.
  (a) What are the SI units of A and B?
  (b) What impulse does this force impart to the object?

Question 2

If the maximum possible accuracy in measuring the lifetime of a particle increases, the maximum possible accuracy in measuring its energy will
 
  A) increase.
  B) decrease.
  C) not be affected.

[pallen55]

Answer to Question 1

(a) A: N/s4 = kg  m/s6 , B: N/s2 = kg  m/s4 (b) 12.9 N  s, horizontally

Answer to Question 2

B