Recent content by checkmarks

Homework Statement A tuning fork vibrating at 512 hertz falls from rest and accelerates at 9.81 m/s^2. How far below the point of release is the tuning fork when waves of frequency 485 Hz reach the release point? take the speed of sound in air to be 340 m/s. (don't forget it takes the sound...

Homework Statement a) A converging lens with a focal length of 15cm has an object 5cm tall placed 40cm to the left of it. To the right, 30 cm away, is a converging lens of focal length 10cm. use the thin lens and magnification formulae to locate the finale image. Find its magnification. b)...

Homework Statement How much work is done by an Olympic triathlete who accelerates herself on her bicycle (combined mass of 105kg) from 5 m/s to 10 m/s? Homework Equations Ek = 1/2mv^2 W = Fapp(d) The Attempt at a Solution Ek = 1/2m[(5 + 10)/2]^2 how do i go about solving this?

Homework Statement A 0.2 kg block of ice at -15*C is placed into a pan on a stove, heated to a liquid, and then to vapour with a final temperature of 115*C. Calculate the total amount of heat required for this process. Homework Equations Eh = mc(t2 - t1) Lf (or Lv) = Eh / m The...

Homework Statement An object of mass 12.5 kg hangs from very light pulleys as shown here: http://i26.tinypic.com/24lq5b4.jpg What force must be applied to the rope so that the mass stays at rest? Homework Equations Fnet = ma... The Attempt at a Solution I am really clueless when it...

Homework Statement A ball of mass 240 g is moving through the air at 20.0m/s with a gravitational potential energy of 70J. With what speed will the ball hit the ground? Homework Equations Eg = mgh Ek = 1/2mv^2 W = mgd The Attempt at a Solution this is what i did: at 0m, potential...

Homework Statement A parachutist of mass 70kg, in free fall at 136 km/h, opens a parachute. if the chute creates a 895 N air resistance force and the parachutist is being pulled down by a force of gravity at 686 N a) find hte acceleration of the parachutist b) how far does she fall in 5.0 s...

thank you so much!

isn't it? if the cat isn't moving on the ball and the ball is still? hmm...i can only think of a few...please expand? thankss

This isn't a problem, its just an assignment I've been given. I need to draw the FBD of an object/person at rest that has 10 or 11 forces on it. I was thinking of using this: http://www.canada-shops.com/Stores/michaelrodents/Images/Category/190372.jpg but i can only think of 5 forces so far...

Homework Statement Given the following conditions, what is the relative velocity of 2 cars if their ground speeds are 80km/h for Car A and 45 km/h for Car B? a) both cars are heading in the same direction, A behind B in the reference frame of A b) Use the reference frame of B for part A) c)...

Homework Statement A plane flies a square route with each side 1500m in length (north, west, south then east) If a wind was blowing from the east at 20 km/h the entire trip, find the total time it will take for the plane to complete the journey, given that the plane is flying at 80 km/h...