Answer:
In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.
Answer:
(a) Negative Q
(b) Positive Q
Explanation:
Charge is the inherent property of matter due to the transference of electrons.
There are three methods of charging a body.
(i) Charging by friction: When two uncharged bodies rubbed together, then one body gets positive charged and the other is negatively charges it is due to the transference of electrons form one body to another.
(ii) Conduction: when a charged body comes in contact with the another uncharged body, the uncharged body gets the same charge and the charge is distributed equally.
(iii) Induction: When a uncharged body keep near the charged body, the uncharged body gets the same amount of charge but opposite in sign.
(a) When a small tack of charge Q is lowered into the hole, then due to the process of induction, the charge on the inner surface of the shell is - Q.
(b) Due to the process of conduction, the charge on the outer surface of the shell is Q.
The best thermal conductor is b. metal
Answer:
0.163 s
Explanation:
Appying,
P = mgh/t................ Equation 1
Where P = power of the motor, m = mass of the suitcase, h = vertical distance, t = time, g = acceleration due to gravity.
make t the subject of the equation,
t = mgh/P................ Equation 2
Given: m = 20 kg, h = 50 cm = 0.5 m, P = 0.6 kW = 600 W
Constant: g = 9.8 m/s²
Substitute these values into equation 2
t = (20×0.5×9.8)/600
t = 0.163 s
