in terms of forces, explain why there is a risk of head injury when diving from this height and sugest why the drivers choose to enter the water feet first

What is the difference between electrically neutral objects and electrically charged objects

Atrain departs from its station at a constant acceleration of 5 m/s. what is the speed of the train at the end of 20s?

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?