' B ' is the only true one.
This is the same question that I just answered.
Have present the definition of acceleration:
a = Δv / Δt, this is change in velocity per unit of time.
a and v are in bold to mean that they are vectors.
1) a body traveling in a straight line and increasing in speed: CORRECT:
Acceleration is the change in velocity, either magnitude or direction or both. So, a body increasing in speed is accelerated.
2) a body traveling in a straight line and decreasing in speed: CORRECT
A decrease in speed is a change in velocity, so it means acceleration.
3) a body traveling in a straight line at constant speed: FALSE.
That body is not changing either direction or speed so its motion is not accelerated but uniform.
4) a body standing still : FALSE.
That body is not changind either direction or speed.
5) a body traveling at a constant speed and changing direction: CORRECT.
The change in direction means that the body is accelerated. The acceleration due to change in direction is named centripetal acceleration.
Answer:
Only magnetic field present
Explanation:
Since, the positively charged particle does not speed up or slow down, but it does deflect in the downward direction. This means only magnetic field is present.
This is because electric field changes the velocity and magnetic field changes the direction.
The magnetic force F is given by
F = qvBsinθ
Where, q = charge magnitude, v = velocity of charge, B = strength of magnetic field. and θ =the angle between the directions of v and B.
<h2>
So, the correct answers are:</h2>
Travels in longitudinal waves
Travels most slowly through a gas
Speeds up when temperature is increased
Is caused by vibration
Explanation for correct answers:
Yes, it does travel in longitudinal waves
Yes, sounds weird, but travels faster in the water
Yes, does speed up when temperature is increased
And yes, Is caused by vibration.
<h2>
Wrong answer is:</h2>
Can travel through a vacuum
Explanation for wrong answer:
actually, in space, there is NO sound, because there are no particals for the sound to vibrate with, there's just empty SPACE.
Answer:
x₂=0.44m
Explanation:
First, we calculate the length the spring is stretch when the first block is hung from it:
Now, since the stretched spring is in equilibrium, we have that the spring restoring force must be equal to the weight of the block:
Solving for the spring constant k, we get:
Next, we use the same relationship, but for the second block, to find the value of the stretched length:
Finally, we sum this to the unstretched length to obtain the length of the spring:
In words, the length of the spring when the second block is hung from it, is 0.44m.
