How does friction change energy? 1 Energy lost from machine changes into heat energy.
2 Friction causes energy to disappear.
3 Friction causes energy to get destroyed.
4 Energy changes from heat energy to mechanical energy.

Two identical small charged spheres are a certain distance apart, and each one initially experiences an electrostatic force of magnitude f due to the other. with time, charge gradually leaks off of both spheres. when each of the spheres has lost half its initial charge, the magnitude of the electrostatic force will be

Select the word from the list that best fits the definition classification of most stars on the h-r diagram

Astudent pushes on a 20.0 kg box with a force of 50 n at an angle of 30° below the horizontal. the box accelerates at a rate of 0.5 m/s2 across a horizontal floor. what is the value of the normal force on the box? 200 n 243 n 156 n 225 n