Explanation:
Rest and motion are relative terms. A body at rest with respect to one observer may be in motion with respect to another observer. For example a person sitting in a moving train is at rest with respect to the train.
It depends on the length of the string and the speed its swinging at. If its short then it will reach the full swing in less of a time but if its a longer string then it would take a longer time to make a full swing.
Answer:
Explanation:
Charge on uranium ion = charge of a single electron
= 1.6 x 10⁻¹⁹ C
charge on doubly ionised iron atom = charge of 2 electron
= 2 x 1.6 x 10⁻¹⁹ C = 3.2 x 10⁻¹⁹ C
Let the required distance from uranium ion be d .
force on electron at distance d from uranium ion
= 9 x 10⁹ x 1.6 x 10⁻¹⁹ / r²
force on electron at distance 61.10 x 10⁻⁹ - r from iron ion
= 9 x 10⁹ x 3.2 x 10⁻¹⁹ / (61.10 x 10⁻⁹ - r )²
For equilibrium ,
9 x 10⁹ x 1.6 x 10⁻¹⁹ / r² = 9 x 10⁹ x 3.2 x 10⁻¹⁹ / (61.10 x 10⁻⁹ - r )²
2 d² = (61.10 x 10⁻⁹ - r )²
1.414 r = 61.10 x 10⁻⁹ - r
2.414 r = 61.10 x 10⁻⁹
r = 25.31 nm .
Anyways the answer is x=2
Answer:
(c) increase by a factor of four
Explanation:
the formular for the relationship between energy and current is E= I²Rt (Heat energy)
the heater is fairly independent of its temperature , and given the time to be constant.
with the current being doubled,
E = I² Rt
E/ I² = K
=
E2 = 
I2 = 2* I1
E2 = E1 * 4*I1² / I1²
dividing , we have that E2 = 4 * E1
which means during the same time interval the amount of energy will increase by a factor of four.
