Answer:
20 km/h
Explanation:
45 km ÷ 2.25 hours (15 mins is 0.25 hours)
= 20
20 km/h
Understanding Newtons second law that everything has an equal and opposite reaction. The reaction force from a balloons air being pushed out is the preasurized air it had to push out into the open air.
Because force always has a direction, it always works towards or against something.
you might know that force,
is rate of change of momentum i.e
force = m (v-u)/t
= (mv - mu )/ t
as we know momentum is a vector quantity so, the rate of change of momentum i.e Force would also be a vector quantity.
momentum = mass × velocity
velocity has a direction so,
momentum has also got a direction.
so, momentum is also a vector quantity.
Answer:
correct option is A. Resonance
Explanation:
solution
vibrations in the tube are caused by the Resonance because Resonance cause of sounds production in the musical instrument
As if resonance ( hollow cylindrical tube) immerse in cylinder of water and force in to vibration by tuning fork
As tines of tuning fork vibrate at natural frequency and it create sound wave that impinged up on opening of resonance tube
so correct option is A. Resonance
The only way of telling about dark energy is our observation of how the universe has been expanding. It basically works the opposite as gravity, pushing things away from it. Thus, the closest answer would be D. The shape of galaxies in cluster galaxies.
