Recent content by san512

A) 7.3 m/s B) 12 m/s C) 21 m/s D) 32 m/s E) 42 m/s I get 9.4 m/s

Homework Statement A train moving at a constant speed is passing a stationary observer on a platform. A flute player is playing a note with a frequency of 940Hz. after the flute has passed, the observer hears the sound frequency of 915Hz. What is the speed of the train? The speed of sound in...

Got it. Thanks a lot. You helped me out a lot.

I.m a college student struggling through physics and i find this website very helpful!

i got it. thanks a lot. if you don't mind could you help me with applying significant figures? i have trouble with problems that need a lot conversions. so for example, 12 miles to m. i see 2 in miles so would that mean i have to round m to 2 significant figures as well?

but the question is asking for rotational KE. don't i need to calculate w for that?

okay. so using vf= 2d-vi/t 2*402.25m/15s= 53.63m/s relating linear motion with rotational motion v/r=w 53.63m/s/.23m =233.17 is that right?

how would i find angular velocity and what units am i missing?

Homework Statement The average car today has a mass of 1100 kg, and when accelerating from rest, covers 0.25 miles in 15 seconds. Each rim and tire together has a diameter of 46 cm and a mass of 9.1kg. If we agree the rim and tire have the shape of a solid disk that rotates through its...