Answer:
(A)
Explanation:
We know , electric potential energy between two charge particles of charges "q" and "Q" respectively is given by kqQ/r where r is the distance between them.
Since the two charged particles are moving apart, the distance between them (r) increases and thus electrical potential energy decreases.
Answer:
Max height= 36000 meters
Total Time = 120 seconds
Explanation:
0 = U - at
U = at
U= 20*60
U= 1200 m/s
MAX altitude would be
(U²Sin²tita)/2g
Max height= 1200² *( SIN90)²/(2*20)
Time of FLIGHT
2 * 1200/20
2400/20
120 sec
onds
Answer:

Explanation:
From the exercise we have that

<em><u>To find how far from the edge of the piano does the cat strike the floor, we need to calculate its time first </u></em>

At the end of the motion y=0m

Solving for t
or 
Since the <u>time</u> can't be negative the answer is t=0.73
Knowing that we can calculate how far does the cat strike the floor

Answer:
I can't understand the language....
Answer:
The work done by this force can be found via the following formula

Explanation:
Alternatively, the work done by the object is equal to the elastic potantial energy done by the spring.
