The pressure exerted by a phonograph needle on a record is surprisingly large, due to the very small width of the needle. if the equivalent of 1.25 g is supported by a needle, the tip of which is a circle 0.195 mm in radius, what pressure is exerted on the record, in pascals?

102597.6 Pa

Explanation:

mass, m = 1.25 g

Force, F = m x g = 1.25 x 9.8 x 10^-3 = 0.01225 N

radius, r = 0.195 mm = 0.195 x 10^-3 m

Area, A = πr² = 3.14 x 0.195 x 0.195 x 10^-6 m^2

A = 1.19 x 10^-7 m^2

Pressure is defined as the thrust acting per unit area.

P = Force / Area

P = 0.01225 N / (1.10 x 10^-7)

P = 102597.6 Pa

Thus, the pressure exerted is 102597.6 Pa.

"i have always loved contemporary art and made it a general goal to work within the field. after a few nonprofit internships at museums and galleries, i decided to try the for-profit art world and was offered a job as the ad assistant at the magazine. i much prefer the pace of the for-profit art community and have stayed with the company for three years, with a promotion to an account manager last spring."

i just did this and got a 100.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.