Because the sun is not hitting the light on them and there not as bright like when we see them when it's dark.
Answer:
The more energy a sound has the louder we perceive it
Explanation:
To measure volume we use the unit of decibels – abbreviated to dB. The lowest perceivable volume, meaning the quietest sound humans can hear, is 0 decibels. ... Thus, 60 dB are perceived as twice as loud as 50 dB
Answer;
-Physical model
A physical representation of a real object, such as a globe of the world, is a physical model.
Explanation;
-A physical model is a simplified material representation, usually on a reduced scale, of an object or phenomenon that needs to investigated.
-The model can be used to simulate the physical conditions involved (temperature, waves, speed etc.) and to predict the particular constraints of the situation.
Answer:
132 N
Explanation:
Given that a 1.1 kg hammer strikes a nail. Before the impact, the hammer is moving at 4.5 m/s; after the impact it is moving at 1.5 m/s in the opposite direction. If the hammer is in contact with the nail for 0.025 s, what is the magnitude of the average force exerted by the hammer on the nail
From Newton 2nd law of motion,
Change in momentum = impulse.
Change in momentum = m( V - U )
Substitute all the parameters into the formula
Change in momentum = 1.1 ( 4.5 - 1.5 )
Change in momentum = 1.1 × 3
Change in momentum = 3.3 kgm/s
Impulse = Ft
That is,
Ft = 3.3
Substitute time t into the formula above
F × 0.025 = 3.3
F = 3.3 / 0.025
F = 132 N
Therefore, the magnitude of the average force exerted by the hammer on the nail is 132 N.
