Answer:
2 m/s
Explanation:
Parameters given:
Mass of first skateboard, m = 3 kg
Initial speed of first skateboard, u = 4 m/s
Mass of second skateboard, M = 1 kg
Initial speed of second skateboard, U = 0 m/s
Final speed of second skateboard, V = 6 m/s
Using the principle of the conservaton of momentum, the total initial momentum is equal to the total final momentum.
Momentum is the product of mass and velocity. This implies that:
m*u + M*U = m*v + M*V
(3*4) + (1*0) = (3*v) + (1*6)
12 + 0 = 3v + 6
=> 3v = 12 - 6
3v = 6
v = 6/3 = 2 m/s
The final speed of the 3 kg skateboard is 2 m/s
We could take the easy way out and just say
(110 kW) x (3 hours) = 330 kilowatt hours .
But that's cheap, and hardly worth even 5 points.
If we want to talk energy, let's use the actual scientific unit of energy.
________________________________________________
" 110 kw " means 110,000 watts = 110,000 joules/second .
(3 hours) x (3600 sec/hour) = 10,800 seconds.
(110,000 joules/second) x (10,800 seconds) = 1.188 x 10⁹ Joules
That's
==> 1,188,000,000 joules
==> 1,188,000 kilojoules
==> 1,188 megajoules
==> 1.188 gigajoules
Atsa nawfulotta energy !
It goes back to that "110 kw appliance" that we started with.
That's no common ordinary household appliance. 110 kw is something like
147 horsepower. In order to bring 110 kw into your house, you'd need to
take 458 Amperes through the 240-volt line from the pole. Most houses
are limited to 100 or 200 Amperes, tops. And the TRANSFORMER on
the pole, that supplies the whole neighborhood, is probably a 50 kw unit.
Using the metric units kilometer (km) and meter (m), as seen in the picture of the ladder method example. So, the answer would be 14km = 14000m
Yes, a laboratory balance can accurately measure mass on moon also.
Explanation
The work of laboratory balance is to determine the mass of an object.
Generally, a laboratory balance consists of two pans and it determines the mass of an unknown object by reference with a known mass object.
Also the mass of any object tends to remain constant in all conditions.
The mass has no effect due to gravitational force unlike weight. So the laboratory balance can work accurately in any environment as the mass will be constant in any case.
Thus, if a laboratory balance measures mass accurately on earth, then it will measure mass accurately on moon also as mass is not dependent on gravitational force.
