What makes is the difference between speed and velocity
2 answers:
You might be interested in
Answer:
v= 14.85 m/s
Explanation:
- When at the bottom of the dip, the only force that keeps the car in the circular trajectory, is the centripetal force.
- This force is not a new force, is just the net force aiming to the center of the circle.
- In this case, is just the difference between the normal force (always perpendicular to the surface, pointing upward) and the force that gravity exerts on the car (which is known as the weight), pointing downward.
- So, we can write the following expression:
- It can be showed that the centripetal force is related to the speed by the following expression:
- The normal force, it is called the apparent weight, because it would be the weight as measured by a scale.
- Replacing (2) in (1), and solving for Fn, we get:
- Now, we need to find the value of v that makes Fn, exactly 15% more than the weight m*g, so we can write the following equation:
- Replacing Fg by its value, simplifying, and solving for v, we get:
Answer:
a)
b) Ball 1 has a greater speed than ball 2 when they are passing.
c) The height is the same for both balls = 3h/4.
Explanation:
a) We can find the time when the two balls meet by equating the distances as follows:
Where:
: is the initial height = h
: is the initial speed of ball 1 = 0 (it is dropped from rest)
(1)
Now, for ball 2 we have:
Where:
: is the initial height of ball 2 = 0
(2)
By equating equation (1) and (2) we have:
Where the initial velocity of the ball 2 is:
Since = 0 at the maximum height (h):
Hence, the time when they pass each other is:
b) When they are passing the speed of each one is:
For ball 1:
The minus sign is because ball 1 is going down.
For ball 2:
Therefore, taking the magnitude of ball 1 we can see that it has a greater speed than ball 2 when they are passing.
c) The height of the ball is:
For ball 1:
For ball 2:
Then, when they are passing the height is the same for both = 3h/4.
I hope it helps you!