Answer:
Explanation:
A charge is produced when an atom losses or gains an electron. The law of static electricity states that like charges repels, while unlike charges attracts.
1. To determine the charge on the polystyrene rod.
Place the polystyrene rod on the non-conducting rotating stand, and bring the positively charged rod close to it. If attraction occurs, it shows that it is oppositely charged. If repulsion occurs, it shows that it is positively charged.
Bringing a negatively charged rod close to the rotating polystyrene rod would attract it if the charge is opposite. But if the charge on the two rods are the same, repulsion occurs.
2a. When the polystyrene rod is positively charged, it would attract the negatively charged rod but repel the positively charged rod.
b. When the polystyrene rod is negatively charged, it would repel the negatively charged rod but attract the positively charged rod.
c. When the polystyrene rod is uncharged, no reaction would be observed when either the positively charged or negatively charged rod is brought close to it.
Answer:
Possible options:
A. nA, nC, nB
B. nA, nB, nC
C. nC, nB, nA
D. nC, nA, nB
E. nB, nA, nC
Answer is D
Explanation:
When the light is refracted into liquid B it is bent away from the normal, so that nA > nB. When the light is refracted into liquid C it is bent toward the normal, so that nC > nA. Therefore, we conclude that nC > nA > nB
Answer:
40,000N
Explanation:
Force = Acceleration × Mass
2000×20=40,000
Answer:
a) 
, b) 
Explanation:
a) The maximum height is obtained with the help of the First and Second Derivative Tests:
First Derivative
Second Derivative
(absolute maximum)
The maximum height reached by the ball is:
b) The time required by the ball to hit the ground is:
Just one root offers a solution that is physically reasonable:
The velocity of the ball when it hits the ground is:
Work done is given by 1/2kx^2
18 = 1/2*k*0.9*0.9
36 = k*0.81
44.4 = j/m^2
