A device used in radiation therapy for cancer contains 1.40 g of
cobalt 2760Co (59.9333819 u). The half-life of 2760Co is 6.69 yr.
Determine the activity of the radioactive material

Sherlock Holmes is using a 13.4 cm focal length lens as his magnifying
glass. To obtain maximum magnification, how far away must the object
be placed (assume a normal eye)?
What will be the magnification?

The K particle has a charge of -e and contains one quark and one
antiquark. (a) Which quarks can the particle not contain? (b) Which
antiquarks can the particle not contain?

A girl rotates a ball in a string in uniform circular motion above her head
in a horizontal circular. Next she increases the tension force to twice its
original value while keeping the radius constant. How is the new motion
different from before? That is,

A container or crown class (n=1.52) holds a small quantity of ethyl
alcohol (n=1.361) what is the critical angle for internal reflection
of a ray in the glass when it is incident on the glass to liquid
surface?
A different liquid is poured into the contai

Based on a sliding rod generator in the diagram that is being pulled to
the left at constant speed what is the direction of the current through the
resistor, what is the speed of the rod, and how much force must be put
on the rod?
L=33 cm, B=0.55T, R=6 oh

A string along which waves can travel is 2.70 m long and has a mass of
260.0 g. The tension in the string is 36.0 N. What must be the frequency
of traveling waves of amplitude 7.70 mm for the average power to be
11.0 W?

A wire 60.0 mm long is bent in a right angle such that the wire starts at
the origin and goes in a straight line to x = 25.0 mm , y = 0, and then in
another straight line from x = 25.0 mm , y = 0 to x = 25.0 mm , y =
35.0mm . The wire is in an external un

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A garden hose having an internal diameter of 0.710 in. ( 1.8034 cm ) is
connected to a lawn sprinkler that consists merely of an enclosure with
24 holes, each 0.050 in. ( 0.1270 cm ) in diameter. If the

Radioactive decay can be used to determine the age of an object. If you
know the number of radioactive nuclei with which an object started, the
number of radioactive nuclei currently present, and the half-life of the
isotope, you can calculate the time si

A bob on a 0.6m long string is rotated in a vertical circle. When the bob
is in the position when the string makes a 45 degree angle above the
horizontal, centripetal acceleration is 25m/s^2. Find the tangential
acceleration at this point and the speed of

(a)In what fundamental way is mass spectrometry related to Thomsons
cathode-ray experiments?
(b) What are the labels on the axes of a mass spectrum?
(c)To measure the mass spectrum of an atom, the atom must first lose
one or more electrons. Why is this so

A 61.5 kg painter is on a uniform 25.5 kg scaffold supported from above by
ropes. There is a 5.0 kg pail of paint to one side, as shown.
How close to the end can he approach safely?

The figure shows two packages that start sliding down a 20 ramp from
rest a distance d = 7.0 m along the ramp from the bottom. Package A
has a mass of 2.5 kg and a coefficient of kinetic friction 0.20 between it
and the ramp. Package B has a mass of 8.0 k

A 500 g block on a frictionless surface is attached to a rather limp spring
of constant k = 8.7 N/m. A second block rests on the first, and the whole
system executes simple harmonic motion with a period of 3.5 s. When
the amplitude of the motion is increa

An aluminum alloy hollow metal sphere ( =25x10^-6/C) with a radius of
1 meter is exposed to an 111C temperature increased. What is the
percent increased of its volume?
I know its 0.83% but I'll like to know how to solve it please
*
Linear temperature expa

If the lens is equiconvex and has index of refraction(n)1.50, find the
magnitude of it's radii of curvature. In order to do this you will use the
Lensmaker's Equation.
In this equation
is the focal length of the lens: 5.19 cm
is the index of refraction:1.

One light ray from a fish dorsal fin-tip under-water (n=4/3) enters air at
x=0 exactly along the Normal ; another light ray from the fin-tip enters
air at x=0.1 [m] , at a 5.0 angle from the water surface Normal.
Snell will tell you where the light is rea

The distance between atoms in a solid is usually around 2.0*10^-10 m.
Because this is much smaller than the wavelength of visible light, visible
light cannot be used to study the structure of solids. X-rays and
electrons are commonly used.
What is the wav

A wheel of radius r1 = 0.8 m and hub of radius r2 = 0.4 m is shown in the
diagram. Two masses are hung from the wheel-hub system. The
mass m2, on the left, is hung from the hub. The mass m1 is hung from
the wheel. The system is in equilibrium. The moment

A 2.00-m-long metal bar is pulled to the right at a steady
4.7m/s perpendicular to a uniform, 0.770-T magnetic field. The bar rides
on parallel metal rails connected through R = 25.6 , as shown in the
figure (Figure 1) , so the apparatus makes a complete