Recent content by CherryWine

Homework Statement For the first half of a straightly traveled path which is α=60° from some reference line, a body is moving with a velocity of v1=72 km/h. During the second half of a straightly traveled path, the body is moving with an angle of β=30° with a velocity of v2=36 km/h.What is the...

Homework Statement A boat is crossing a river between via points A and B which are d=400m apart. The speed of the river is V2=2 m/s and is constant along the AB line. The angle of the boats trajectory is α=45 degrees. At what speed V2 and with what angle β should the boat be directed so that it...

The problem is only solvable if the "move towards" case is considered as both bodies moving in the same direction (only one of them facing the other). However, the problem arose since this is not clear from the text of the problem.

Can you please explain why would Δd = s1-s2 in the case of them moving towards? Suppose they move with the same velocity, thus they cover equal distances in equal time intervals, therefore by your reasoning Δd would be zero, when obviously it is not!

They do not "catch" in any case. Imagine that their initial distance is infinite. Mentioned scenarios are separate.

What ?! The mentioned speeds/velocities are constant, meaning the acceleration is zero.

Homework Statement Two bodies are moving on the same line. When they move away from each other the distance between them changes for 16m in a time interval of 3 s (Δd1 = 16 m ; Δt1 = 3 s). When they move towards each other the distance between them changes for 3 m in a time interval of 3 s (Δd2...

It's solved guys. For anyone that might have the same problem here's the probable solution: go to the Evaluation tab and from there quit your local kernel. This will delete any saved symbolic or functional assignments you've given somewhere before in Mathematica. Specifically in my problem, I...

I need to define a function that integrates a function in some interval and returns its numerical value. I am not allowed to use built in functions for integrating in Mathematica. This is my code that won't work: http://pokit.org/get/?93856fe8f2070ba781028f8634b9ac3a.jpg This is a code from a...

Homework Statement In a copper calorimeter of mass m=100g, there is water of mass m1=200g with a temperature of t1=4°C. A copper body of mass m2=300g and temperature t2= - 20°C is inserted into the calorimeter. a) What will be the final temperature inside the calorimeter? b) Show that one...

Oh. Thank you very much. Now I need to forgive myself for being an undergrad that is confused with such trivial things. I will try to solve the problem once again. Thanks again.

But what should I do then with the negative gravitational potential energy? This is really confusing me.

But isn't the expression for gravitational potential energy itself negative? So by plugging in the signs in KEi+PEi=KEf+PEf I would obtain KEi-PEi=KEf-PEf ?

Homework Statement An object is fired upwards with an initial velocity that is less than escape velocity. Show that the maximum height obtained by the object is equal to H=(R*H')/(R-H') where R is the radius of the Earth and H' is the height that the body would obtain if the gravitational field...

I know that this question has been asked many times before on this forum, but on every existing thread either the question or the answers, or both, were too vague. I understand that inertial mass is defined as the property of an object to resist change of its velocity, that is the mass that...