60 J of work is done to stretch a spring with spring constant 7.5 Ncm-1 from its natural length of 0.24 m to some new length. Work out this new length.

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?

What do you think car designers do if the damage caused by a crash test is too severe?

Polly is pushing a box across the floor with a force of 30 n. the force of gravity is –8 n, and the normal force is 8 n. which value could describe the force of friction if polly could not move the box?