The answer is <span>A. Speed=100 million m/s and frequency = 50 million Hz.</span>
Let's calculate for each choice the wavelength using the equation:
v = f × λ ⇒ λ = v ÷ f<span>
where:
v - the speed,
f - the frequency,
</span>λ - the wavelength.
A:
v = 100 000 000 m/s
f = 50 000 000 Hz = 50 000 000 1/s (Since f = 1/T, so units are Hz = 1/s)
⇒ λ = 100 000 000 ÷ 50 000 000 = 2 m
B:
v = 150 000 000 m/s
f = 1 500 Hz = 1 500 1/s
⇒ λ = 150 000 000 m/s ÷ 1 500 = 100 000 m
B:
v = 300 000 000 m/s
f = 100 Hz = 100 1/s
⇒ λ = 300 000 000 m/s ÷ 100 = 3 000 000 m
According to these calculations, the shortest wavelength is needed for choice A.
Answer:
Air resistance slows down the ball
In space, there would be no air resistance
Explanation:
When an object moves through the air, there is a force acting in the opposite direction to the motion of the ball: this force is called air resistance.
Air resistance is due to the friction between the molecules of air and the molecules at the surface of the object - because of this frictional force, the object is slows down in its motion and loses some energy (which is converted into thermal energy of the surrounding air).
There is also the force of gravity (downward) that acts on the ball: however, this force does not slows down the ball in its motion, instead it accelerates it towards the ground.
In space, however, there is no air and no gravity. This means that there are no forces acting on the ball: therefore, the ball will not be slowed down, and therefore will continue its motion forever, at constant velocity, according to Newton's first law:
<em>An object at rest (or in motion) will stay at rest (or in motion at constant velocity) when the net external force acting on it is zero</em>
Answer: 109.4 mm
Explanation: <u>Distance</u> is a scalar quantity and it is the measure of how much path there are between two locations. It can be calculated as the product of velocity and time: d = vt
The separation between the two steamrollers is 105 mm or 0.105 m. They collide to each other at the middle of the separation:
location of collision = 
= 0.0525 m
To reach that point, both steamrollers will have spent
t = 0.04375 s
The fly is travelling with speed of 2.5 m/s. So, at t = 0.04375 s:
d = 2.5*0.04375
d = 0.109375 m
Until it is crushed, the fly will have traveled 109.4 mm.
As we know that
here we know that
now by the above formula we will have
