Recent content by Elaine Jane

A concrete highway is built of slabs 11m long (at 23oC). How wide should the expansion cracks be (at 23oC) between the slabs to prevent buckling if the annual extreme temperatures are -30oC and 54oC?(The coefficient of linear expansion of concrete is 12x10-6 oC^-1) Please help, so lost...

A person standing a certain distance from an airplane with four equally noisy jet engines is feeling a sound level intensity bordering on pain, 118 dB. What sound level intensity would this person experience if the captain shuts down all but one engine? Looking for final numerical answer and a...

A wheel starts from rest and rotates about its axis with constant angular acceleration. After 5.4s have elapsed, it has rotated through an angle of 20 radians. What is the angular velocity when the time t = 5.4 s? For reference, I got 3.704 radians/second as my answer. Am I wrong? If so, please...

It takes a force of 65 N to compress the spring of a toy popgun 0.2 m to "load" a 0.1 kg ball. With what speed will the ball leave the gun? Lost! Please help!!! Looking for correct final answer (in m/s) and a simple, easy-to-follow explanation. Thank you soo much!!

A car of mass 1430 kg traveling at 24 m/s is at the foot of a hill that rises 105 m in 2.2 km. At the top of the hill, the speed of the car is 12 m/s. Find the average power delivered by the car's engine, neglecting any frictional losses. Please help, thank you! Best answer to the answerer who...

Jane, looking for Tarzan, is running at top speed (5.4 m/s) and grabs a vine hanging vertically from a tall tree in the jungle. How high can she swing upward?(g = 9.8 m/s^2). Please help!! Looking for numerical final answer and simple explanation. Thank you so much!!