# physics

The disk shaped head of a pin is 1.0 mm in diameter.
Which of the following is the best estimate of the number of atoms in the layer of atoms on the top of the surface of the pinhead?

1. 10 to the 34th power
2. 10 to the 19th power
3. 10 to the 24th power
4. 10 to the 29th power
5. 10 to the 14th power
6. 10 to the 4th power
7. 10 to the 9th power

1. 👍 0
2. 👎 0
3. 👁 1,221
1. The pin head's volume is
V = (pi/6*D^3 = 0.5*10^3 mm^3
= 0.5*10^-3 cm^3.

Assume the pin is steel. The density is about 8 g/cm^3 and the pinhead mass is 4*10^-3 g. The mean molecular mass of the most abundant metal in the steel (iron) is 56 g/mole, so there are
4*10^-3/56 = 7*10^-5 moles in the pinhead. Multiply that by Avogadro's number for the number of atoms.

I get 4*10^19

Your nearest estimate to that is #2. (10^19)

1. 👍 0
2. 👎 0
2. 10^14.
Divide area of pinhead by area of atom

1. 👍 2
2. 👎 0
3. eeifhuiugfjwuyejdsbcygwychdbcgwwgvucyehiodjdyguyjdvjbdiph

figffewfgew9gfiefbsjvhvvigygewufiekjckjsjf-09r0948grhjvb7fy4r=uhefguyfwefjkdsicg
hvgyuguvhbfyfev;vyh
hvirgigvbh
bhifbvib hiuhfiuhhfighufha
abfjhggihhgfdhuidsfkjsljlkjfklf
afkhfhifgvhjfbv

1. 👍 1
2. 👎 2

## Similar Questions

1. ### physics

You've taken your neighbor's young child to the carnival to ride the rides. She wants to ride The Rocket. Eight rocket-shaped cars hang by chains from the outside edge of a large steel disk. A vertical axle through the center of

2. ### Physics

1. A cylindrical disk of wood weighing 45.0N and having a diameter of 30.0 cm floats on a cylinder of oil of density 0.850 g/cm3. The cylinder of oil is 75.0 cm deep and has the same diameter of the wood. (a) What is the gauge

3. ### Physics

The diameter of our disk-shaped galaxy, the Milky Way, is about 1.7E+5 light-years (ly). The distance to the Andromeda galaxy, which is the spiral galaxy nearest to the Milky Way, is about 1.9E+6 ly. If a scale model represents

4. ### physics

20 kg , 30 cm diameter disk is spinning at 300 rpm. How much friction force must be applied to rim to bring the disk to a halt in 3.0s?

1. ### physics

a bolwing ball of mass 2.00 kg strikes a stationary pin of mass 5.00 x 10^2 g. the collision lasts for .60s after which the pin moves off with a velocity of 12.0 m/s [w] a)accel of pin during the collision b)force exerted by

2. ### Scientific Notation

The point on a pin has a diameter of about 1 * 10^-4 meters. If an atom has a diameter of 2 * 10^-9 meters, about how many atoms could fit across the diameter of the point of a pin?

3. ### chemistry

Why is it possible to float a pin on the surface of water? A. The molecules of water on the surface change bonding as they dry out. B. The density of the pin is less than that of the water's surface. C. The surface tension of the

4. ### Physics

The figure shows an arrangement in which four disks are suspended by cords. The longer, top cord loops over a frictionless pulley and pulls with a force of magnitude 93.4 N on the wall to which it is attached. The tensions in the

1. ### physics

A 4.0 kg, 36-cm-diameter metal disk, initially at rest, can rotate on an axle along its axis. A steady 5.5 N tangential force is applied to the edge of the disk. What is the disk's angular velocity, in rpm, 4.0 s later?

2. ### physics

The anchor shackle supports a cable force of 600 lb. If the pin has a diameter of 0.25 in., determine the average shear stress in the pin.

3. ### Physics 1

The hard disk in a laptop computer contains a small disk that rotates at a rate of 5000 rpm. If this disk has a radius of 2.3 cm, what is the centripetal acceleration of a point at the edge of the disk?_____m/s^2

4. ### PHYSICS

An irregularly shaped plastic plate with uniform thickness and density (mass per unit volume) is to be rotated around an axle that is perpendicular to the plate face and through point O. The rotational inertia of the plate about