Heated air rises while cooled air sinks.
Answer:
Option B is correct.
A double insulated drill generally has a plastic case with the electrical connections and motor insulated within the tool
Explanation:
A double insulated drill's design in real life has plastic casing as the insulator & it wouldn't be a drill without its motor now, would it!?
Answer:
The inner planets (in order of distance from the sun, closest to furthest) are Mercury, Venus, Earth and Mars . the outer planets, Jupiter, Saturn, Uranus and Neptune
Explanation:
Answer:
a) 
b) 
Explanation:
The frequency of the
harmonic of a vibrating string of length <em>L, </em>linear density
under a tension <em>T</em> is given by the formula:

a) So for the <em>fundamental mode</em> (n=1) we have, substituting our values:

b) The <em>frequency difference</em> between successive modes is the fundamental frequency, since:

Answer:
P = 450 J
Explanation:
Given that,
Mass of a child, m = 18 kg
The vertical distance from the top to the bottom of the slide is 2.5 metres.
The Gravitational field strength = 10 N/kg
We need to find the decrease in gravitational potential energy of the child sliding from the top to the bottom of the slide.
The formula for the gravitational potential energy is given by :
P = mgh
Substituting all the values,
P = 18 kg × 10 m/s² × 2.5 m
P = 450 J
Hence, the decrease in gravitational potential energy is 450 J.