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A cyclist rides 10km. In the first 5km, they climb a hill, averaging 10km/h. In the second 5km, they descend the hill, averaging 30km/h. What is their average speed over the full 10km?

A common response from the student for the above question is: “I got 20km/h but it says it’s wrong! help i’m really confused”. The following two paragraphs will outline how I might attempt explain this idea ...
SB
Answered by Shihabul B. • Physics tutor
3784 Views

A hot air balloon is travelling at a speed of 5.0m/s at an angle of 60.0 degrees up from the horizontal. Find the vertical and horizontal components.

The diagram would have the following: An arrow pointing upwards labeled v(y) An arrow pointing to the right labeled v(x) An arrow pointing in between those lines with a degree between this one and the right ...
MB
Answered by Marta B. • Physics tutor
2723 Views

Define the resistivity of a metal wire

ρ = (AR) / l where: ρ is the resistivity of the metal wire A is the cross sectional area of the specimen wire R is the electrical resistance of a uniform metal wire l is the length of metal wire through whic...
JE
Answered by Javier E. • Physics tutor
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What is wave-particle duality?

As you may have already seen, light sometimes behaves as a wave and sometimes as a particle. This is due to something we call "wave-particle duality" by which we mean that objects on the quantum sc...
PZ
Answered by Petr Z. • Physics tutor
2631 Views

What happens to ice when energy is supplied at a constant rate in terms of the changes in energy of the molecules?

If we start with water at 263K (ice) then the molecules are positioned in a regular lattice structure held in place by hydrogen bonds. The molecules have some vibrational energy but not much translational en...
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Answered by Stuart D. • Physics tutor
2701 Views