Answer:
Energy due to air resistance = 31.8 Joules
Explanation:
According to the law of conservation of energy, energy can neither be created nor destroyed but can be transformed from one form to another
Kinetic Energy + Energy due to air resistance = Potential energy..........(1)
If there is no energy loss due to air resistance, potential energy = kinetic energy
mass, m = 1.5 kg
height, h = 4.0 m
speed, v = 6 m/s
Kinetic energy = 0.5 mv²
Kinetic energy = 0.5 * 1.5 * 6²
Kinetic energy = 27 Joules
Potential Energy = mgh
Potential energy = 1.5 * 9.8 * 4
Potential energy = 58.8 Joules
From equation (1)
27 + Energy due to air resistance = 58.8
Energy due to air resistance = 58.8 - 27
Energy due to air resistance = 31.8 Joules
Using
KE = ½mv² = ½×1500×19×19 = 270750 joules
Answer: 90 km/hr
Explanation:
Speed= distance divided by time
540/6
= 90km/hr
Answer:
longer for less massive stars.
Explanation:
A star is a giant astronomical or celestial object that is comprised of a luminous sphere of plasma, binded together by its own gravitational force.
It is typically made up of two (2) main hot gas, Hydrogen (H) and Helium (He).
Some of the examples of stars are Canopus, Sun (closest to the Earth), Betelgeus, Antares, Vega etc.
Generally, the time taken for the collapse of an interstellar cloud fragment to the period (time) when a main-sequence star is given birth to, is usually longer for less massive stars.
This ultimately implies that, stars that are not so massive or big in size are transformed from interstellar cloud fragment to a main-sequence star is lesser.
-- There's a force of 240N pushing her backwards.
-- She's maintaining a steady speed (of 2.5 m/s) .
-- In order to maintain a steady speed (no acceleration),
the forces on her must be balanced. So she's maintaining
a steady force of 240N forward.
-- Every time she moves 1 m forward, she does work of
(force) x (distance) = 240 joules.
-- She moves 2.5 meters forward every second.
So she's doing (240 x 2.5) = 600 joules of work every second.
-- 600 joules per second = 600 watts .
