Answer:
a). whenever the ball is at it's highest on either side (it stops, so kinetic energy is 0)
b). whenever the ball is at the bottom (A) - it cannot go lower, so potential energy is 0.
c). whenever the ball accelerates, so when it's going down from either side before reaching A (at that point it's going up and thus slowing down).
d). whenever the ball is ascending, so when it's goind up from A to either side
Explanation:
Kinetic energy is based on velocity
mass is constant, so we need to find a point where v = 0 to solve a), and points where v is increasing to solve b).
Potential energy is based on height vs "the bottom" (here, the minimum altitude is "the bottom").
mass and gravitational acceleration are constant, so we need to find a point where h = 0 to solve b) and the points where h is increasing to solve d).
Answer:
7.1 Hz
Explanation:
In a generator, the maximum induced emf is given by
where
N is the number of turns in the coil
A is the area of the coil
B is the magnetic field strength
f is the frequency
In this problem, we have
N = 200
B = 0.030 T
So we can re-arrange the equation to find the frequency of the generator:
Given that,
Frequency emitted by the bat, f = 47.6 kHz
The speed off sound in air, v = 413 m/s
We need to find the wavelength detected by the bat. The speed of a wave is given by formula as follows :
or
So, the bat can detect small objects such as an insect whose size is approximately equal to the wavelength of the sound the bat makes i.e. 8.67 mm.