As an airplane moves through the air, its wings cause changes in the
speed and pressure of the air moving past them. These changes result in
the upward force called lift.
The Bernoulli principle states that an increase in the speed of a fluid
occurs simultaneously with a decrease in the pressure exerted by the
fluid.
A wing is shaped and tilted so the air moving over it moves faster than
the air moving under it. As air speeds up, its pressure goes down. So
the faster-moving air above exerts less pressure on the wing than the
slower-moving air below. The result is an upward push on the wing—lift!
Answer:
Because of inertia (Newton's First Law of motion)
Explanation:
According to Newton's First Law of motion:
"An object at rest (or in motion at constant velocity) will tend to stay at rest (or tend to keep moving with same velocity) unless acted upon an unbalanced force"
In this problem, the object we are analyzing is the coffee cup.
At the beginning, the cup is at rest, together with the car.
Later, the car starts moving when the light turns green.
If we apply Newton's First Law of motion to the cup, we see that the coffee cup tends to keep its state of rest: for this reason, as the car moves forward, the coffee in the cup will spill backward, into the rear seat. This property of an object to mantain its state of motion is also called as inertia.
Answer:
The electron’s velocity is 0.9999 c m/s.
Explanation:
Given that,
Rest mass energy of muon = 105.7 MeV
We know the rest mass of electron = 0.511 Mev
We need to calculate the value of γ
Using formula of energy
Put the value into the formula
We need to calculate the electron’s velocity
Using formula of velocity
Put the value into the formula
Hence, The electron’s velocity is 0.9999 c m/s.
Answer:
122.5 N/m
Explanation:
According to the law of conservation of energy, if there is no air resistance or frictional forces, the initial elastic potential energy of the spring toy is entirely converted into gravitational potential energy when the toy reaches the highest point.
Therefore, we can write:
where the term on the left is the initial elastic potential energy while the term on the right is the gravitational potential energy, and where
k is the spring constant
x = 0.02 m is the compression of the spring
m = 0.01 kg is the mass of the toy
h = 0.25 m is the height reached by the toy
is the acceleration due to gravity
Solving for k,
