Answer:
it Give only one of them a positive or negative charge
Answer: Although low frequency sound travels further than high-frequency sound, calls at higher frequencies give the bats more detailed information--such as size, range, position, speed and direction of a prey's flight. Thus, these sounds are used more often.
Explanation:
Complete question:
Two 10-cm-diameter charged rings face each other, 21.0 cm apart. Both rings are charged to +40.0 nC. What is the electric field strength at the midpoint between the two rings ?
Answer:
The electric field strength at the mid-point between the two rings is zero.
Explanation:
Given;
diameter of each ring, d = 10 cm = 0.1 m
distance between the rings, r = 21.0 cm = 0.21 m
charge of each ring, q = 40 nC = 40 x 10⁻⁹ C
let the midpoint between the two rings = x
The electric field strength at the midpoint between the two rings is given as;

Therefore, the electric field strength at the mid-point between the two rings is zero.
Answer: The period of the pendulum will increase. Because of less gravity
Explanation:
Since the force of gravity is less on the Moon, the pendulum would swing slower at the same length and angle and its frequency would be less. Hence more time period will be experienced by the pendulum. On the moon, the acceleration due to gravity g is less when compared to that of the earth.