Launching marble upwards - Find speed

  • Thread starter Thread starter lachlan81
  • Start date Start date
  • Tags Tags
    Marble Speed
AI Thread Summary
To find the speed of the marble when launched, conservation of energy principles indicate that the initial kinetic energy equals the gravitational potential energy at maximum height. The maximum height of 40m translates to a potential energy of 3920 Joules, leading to an initial speed of approximately 28 m/s. At the halfway point, 20m, the marble has both kinetic and potential energy, allowing for a calculation of its speed using energy conservation. The potential energy at 20m is 1960 Joules, resulting in a speed of about 20 m/s at that height. Understanding these energy transformations is key to solving the problem effectively.
lachlan81
Messages
2
Reaction score
0
I cannot work out how to get this question answered.

Question:
A student launches a marble vertically upwards so that it reaches a maximum height of 40m above it's release height. Calculate:

a).The speed of the marble when it is launched.
b). The speed of the marble at the halfway point.:confused:
 
Physics news on Phys.org
Try with conservation of energy. What sort of energy does the marble have the instant it is launched? How about the instant it reaches its maximum height?
 
Ok, thanks for your help.:smile:
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...

Similar threads

Back
Top