# Physics

There are 100 g of lodine-131. After 16 days, how many grams of lodine-131 is left?

3 weeks ago

(b) Explain the behaviour of the light at points Y and Z.ray oflightnot to scaleHelp

3 weeks ago

A 1750-kg car travels at 23 m/s when it crashes into the rear end of a 1500-kg car traveling at 20 m/s in the same direction on nearly frictionless ice. The two cars become stuck together and slide on the ice. How fast do the two cars move together immediately after the collision? *use units*

3 weeks ago

2.A book weighs 6 newtons.A librarian picks up the book from one shelf and puts it on a shelf 2 metres higher.(a) Calculate the work done on the book. [Show your working].(b) The next person to take the book from the shelf accidentally drops it.The book accelerates at 9.8m/s.Use this information to calculate the mass of the book. [Show your working].

3 weeks ago

How does the restoring force and the mass of the string effect the speed of a wave generated on a string?

3 weeks ago

A 500 kg empty elevator moves with a downwards acceleration of 2 m/s2. What is the tension force of the cable on the elevator?

3 weeks ago

We all know the trick of pretending to lose a cell phone connection, but the receiving person (in reality) can usually tell you have a good connection. This time, you are in luck- you are using a cell phone at 850 MHz, on one side of you is the cell phone tower, and on the other side, a tall building.1) what is the wavelength of your cell phone transmission?2) How far from the building should you stand to lose reception?3) Since the phone companies employ good engineers, that trick won't actually work. However, you happen to see a chain-link fence nearby, and (out of desperation) try to use that as a diffraction grating to scatter the radiation. Estimating the link spacing as 5 cm, will this work?

3 weeks ago

A bus slows down from 8.22 m/s to a stop in 13.3 s. Its wheels have a radius of 0.530 m. Find the initial angular speed of the wheels.

3 weeks ago

A sound pulse emitted underwater reflects off a school of fish and is detected at the same place 0.10 s later. How far away are the fish? (Assume the water temperature is 20 degrees C.)

3 weeks ago

Which of the position versus time graphs below matches the following description: a speed versus time graph has a horizontal line at 5 m/s from zero to five seconds?

3 weeks ago

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568681
480985
357176
274132
272936
249918
216424
119193
99545
70262
65481
36431
25365
24518
20622
19413
18387
3100