It could be B or D, but I am fairly certain it is D.
To tackle this issue, it's essential to understand the conversion of pounds to kilograms:
1 lb = 0.45 Kg
By applying a straightforward rule of three
1 lb ---> 0.45 Kg
125 lb ---> x
Solving for x yields:
x = ((125) / (1)) * (0.45) = 56.25 Kg.
Response
her mass in kilograms is 56.25 Kg.
Response:
0.60 m/s
Details:
The average speed between times t = a and t = b can be expressed as:
v_avg = (x(b) − x(a)) / (b − a)
Given the function x(t) = 0.36t² − 1.20t, and considering the interval from 1.0 to 4.0:
v_avg = (x(4.0) − x(1.0)) / (4.0 − 1.0)
v_avg = [(0.36(4.0)² − 1.20(4.0)) − (0.36(1.0)² − 1.20(1.0))] / 3.0
v_avg = [(5.76 − 4.8) − (0.36 − 1.20)] / 3.0
v_avg = [0.96 − (-0.84)] / 3.0
v_avg = 0.60
The average speed calculated is 0.60 m/s.
