ANSWER
625 m/s
EXPLANATION
Given:
• The frequency of the sound wave, f = 250 Hz
,
• The wavelength, λ = 2.5 m
Find:
• The speed of the wave, v
The speed of a wave of wavelength λ and frequency f is given by,
Substitute the known values and solve,
Hence, the speed of the wave is 625 m/s.
Answer:
4) True. The change of direction needs an unbalanced force
Explanation:
Let us propose the resolution of the problem using Newton's second law.
F = m a
As the car is spinning the acceleration is centripetal
a = v2.r
F = m v2 / r
We can see that as the velocity of a vector even if its module does not change, the change of direction requires an external force.
Now we can analyze the statement if they are true or false
1) and 3) False, even when the speed changes, the direction changes
2) False with the speed change can be determined
4) True. The change of direction needs an unbalanced force
5) False are different things. the direction is where it is going and the speed is the magnitude of the vector
She recoil at a high speed than a low
Answer:
, the minus meaning west.
Explanation:
We know that linear momentum must be conserved, so it will be the same before (
) and after (
) the explosion. We will take the east direction as positive.
Before the explosion we have 
.
After the explosion we have pieces 1 and 2, so 
.
These equations must be vectorial but since we look at the instants before and after the explosions and the bomb fragments in only 2 pieces the problem can be simplified in one dimension with direction east-west.
Since we know momentum must be conserved we have:
Which means (since we want 
and 
):
So for our values we have:
Answer:
Once you reach adulthood, you will not experience peer pressure.
Explanation:
We tend to believe that self-control comes from within, but many of our attitudes depend as much on friends and family as on ourselves. That's because at any stage of our life (even the adult stage) our friends and our family have the power to influence us, sometimes that influence is good and sometimes bad, it's up to us to reason about them.
The people around us have the power to make us fat, consume more alcohol, worry less about the environment and expose ourselves to the sun without proper protection, among many other things.
It is not simply about peer pressure, where you deliberately act in a certain way to suit the group. It is, in fact, largely an unconscious attitude. Without your awareness, your brain is constantly picking up cues from people around you to dictate your behavior. And the consequences can be serious.
