Potential energy is first transformed into kinetic energy as she pedals, then gravitational as she coasts down the hill.
Answer:They may cause motion to change
Explanation:They may cause motion; they may also slow, stop, or change the direction of motion of an object that is already moving. Since force cause changes in the speed or direction of an object, we can say that forces cause changes in velocity. Remember that acceleration is a change in velocity.
Using the idea of motion under gravity, it will take 0.5 seconds more before the phone hits the ground.
<h3>What is the distance covered?</h3>
The distance covered is obtained form the equations of kinematics under gravity.
Now;
v = u + gt
Recall that it was dropped from a height hence u = 0 m/s
v = gt
v = 9.8 m/s^2 * 4 s
v = 39.2 m/s
Now;
h = ut + 1/2gt^2
but u = 0 m/s
h = 1/2gt^2
h = 1/2 * 9.8 * (4)^2
h = 78.4 m
The phone will not hit the ground within this time
For the phone to hit the ground;
h = 1/2gt^2
if h = 100 m
100 = 1/2 * 9.8 * t^2
2 * 100/9.8 = t^2
t = √2 * 100/9.8
t = 4.5 seconds
It will take about 0.5 seconds more before the phone will hit the ground.
Learn more about motion under gravity:brainly.com/question/15120445
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Answer:
a) 0.32 m b) -2.4 m c) 1.08 m/s d) -4 m/s
Explanation:
a)
- As the x and y axes (as chosen) are perpendicular each other, the movements along these axes are independent each other.
- This means that we can use the kinematic equations for displacements along both axes.
- In the x direction, as the only initial velocity is in the south direction (-y axis), the skateboarder is at rest, so we can write:

- In the y-direction, as no acceleration is acting on the skateboarder, we can write the following displacement equation:

- For t = 0.6s, replacing by the givens, we get the position (displacement from the origin) on the x-axis, as follows:

b)
- From (2) we can get the position on the y-axis (displacement from the origin) as follows:

c)
- In the x- direction, we can find the component of the velocity along this direction, as follows:

- Replacing by the values, we have:

d)
- As the skateboarder moves along the y-axis at a constant speed equal to her initial velocity, we have:
vfy = voy = -4 m/s
50 miles per hour was Maria’s speed