Only velocity uses direction of travel in its calculations.
$0.60
90 mins is 1.5 hrs
5 kW × 1.5 = 7.5 kWh
7.5 kWh × $0.08 = $0.60
It would not. Imagine four forces equal in magnitude but opposite in direction (e.g. north, east, south, and west). If these forces were to double in magnitude they would still have the same magnitude, meaning the net force is still equal to zero.
Answer:
r₂ = 0.2 m
Explanation:
given,
distance = 20 m
sound of average whisper = 30 dB
distance moved closer = ?
new frequency = 80 dB
using formula
I₀ = 10⁻¹² W/m²
now,
to hear the whisper sound = 80 dB
we know intensity of sound is inversely proportional to square of distances
r₂ = 0.2 m
The sum of the kinetic and potential energies of a system of objects is conserved only when no external force acts on the objects.
<h3>
Conservation of mechanical energy</h3>
The principle of conservation of mechanical energy states that the total mechanical energy of an isolated system (absence of external force) is always constant.
M.A = P.E + K.E
where;
P.E is potential energy
K.E is kinetic energy
Thus, the sum of the kinetic and potential energies of a system of objects is conserved only when no external force acts on the objects.
Learn more about conservation of mechanical energy here: brainly.com/question/24443465
