Answer:
b
c
e
h
Explanation:
Note that the swing direction was not giving in the question and direction could be sideways (in a turn) or in a track or both
The question show something in common ...acceleration
So let's look at the statements and pick the correct ones
a is false while b is correct as the train is accelerating
c is correct. The train is accelerating even thou the speed could not be ascertained
d is false and not feasible as the train is accelerating
e is true as the train maybe moving at a constant speed in a circle
f is false. This could be constant velocity in a circle. Same as g (false)
h is true. It's accelerating
Answer:
f1 = 12.90 Hz
Explanation:
To calculate the first harmonic frequency you use the following formula for n = 1:

( 1 )
It is necessary that the unist are in meters, then you have:
L: length of the string = 60cm = 0.6m
M: mass of the string = 0.05kg
T: tension on the string = 20 N
you replace the values of L, M and T in the expression (1) for getting f1:

Hence, the first harmonic has a frequency of 12.90 Hz
K.E=1/2mv^2 K.E=1/2multiply1multiply8^2=32joules