A: Some physical properties change, but the substance keeps its identity.
Answer: Remember speed is distance divided by time, so if he travels 1000 m in 7.045 s, his speed is
(1000 m)/(7.045 s) = 141.9 m/s.
Note there are 1609 metres in a mile, or 1 mi = 1609 m, so m = 1/1609 mi, or
141.9/1609 mi/s = 0.08822 mi/s. Now, note that 1 h = 3600 s, so the speed is
0.08822*3600 mi/h = 317.6 mi/h.
Answer:
A.The spring constant for B is one quarter of the spring constant for A.
Explanation:
If spring A oscillates at twice the frequency of spring B, and period is frequency inverted. It means spring B has a period twice of spring A's.

As
, and the 2 springs have the same mass




So A.The spring constant for B is one quarter of the spring constant for A. is the correct answer.
Answer:
a,b,c,d,,f, g, j
Explanation:
e) equipotential lines are lines connecting points of equal potential
h) electric field inside the conductor is non-zero even when there is net movement of charge or non-zero current.
i) capacitors' plates are charged and an electric field exists between the plates.