A vibrating stretched string has nodes or fixed points at each end. The string will vibrate in its fundamental frequency with just one anti node in the middle - this gives half a wave.

Rearranging for the wavelength



Therefore the longest wavelength standing wave that it can support is 14m
A cyclic, or not, group can have lots of sets of generators with different cardinalities, a cyclic group is characterized for having a generator set with 1 single element. A generator for a cyclic group and any other element will also be a generator set.
Answer:
40N
Explanation:
Using the newton's second law of motion
\sum Fx = max
Fm - Ff = max
Fm is the applied force
Ff is the frictional force
m is the mas of the cupboard
ax is the acceleration
Since the speed from the lorry is steady, ax = 0m/s^2
Also Ff = 40N
Substitute into the formula;
Fm - 40 = m(0)
Fm - 40 = 0
Add 40 to both sides
Fm - 40 + 40 = 0 + 40
Fm = 40N
Hence the force with which the man applied to push is 40N
The correct choice is D, and it's convection, not conversion.