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Why do astronauts feel weightless while in orbit?

The reason we feel weight isn't because gravity is pulling us down; it's actually because we can feel our body being "squished". When we're on Earth, gravity is trying to pull us down through the f...
AA
Answered by Alex A. • Physics tutor
4574 Views

A rock fragment weighing 50N is displaced from the top of a cliff and falls 0.12 km to the ground. Calculate the kinetic energy (in J) of the rock just before it hits the ground. Assume air resistance is negligible.

Applying the law of conversation of energy, the gravitational potential energy (GPE) stored by the rock before falling is transformed into other types of energy as it falls. Without any external forces actin...
JH
Answered by Jack H. • Physics tutor
2408 Views

Describe how a crumple zone on a car reduces injury to the driver in a crash.

During a crash the velocity of the car is reduced to zero. The deceleration of the car exerts a force on the driver causing injury. Without a crumple zone the change in velocity is instantaneous therefore a ...
TL
Answered by Thomas L. • Physics tutor
3716 Views

Why do things get hot when electricity is pasted through them?

Electricity is the flow of electrons through a material. But for electrons to pass through a material they have to give up some energy, this is called a material's resistance. The energy that is lost from th...
PR
Answered by Peter R. • Physics tutor
2961 Views

Two beakers contain water at room temperature. One contains 200ml, the other 400ml. If both beakers are heated above identical Bunsen burners, which of the two will take longer to boil?

The equation dQ = m c dT tells us how the temperature of an object changes when heat energy dQ is added. In this case the specific heat capacity c is the same for the contents of both beakers since we are he...
KJ
Answered by Keita J. • Physics tutor
7128 Views