The mass of carbon in an animal bone fragment found in an archeology site is 200 g. If the bone registers an activity of 16 Bq, what is its age? Note: 12.0 g of C¹²₆ contains 6.02 x 1023 atoms and C¹⁴₆ / C¹²₆ ~ 1.3x10^-12

Section 1

How far from a -7.40 μC point charge must a 2.00 μC point charge be placed in order for the electric potential energy of the pair of charges to be -0.500 J ? (Take the energy to be zero when the charges are infinitely far apart.)

d = ____ m   (The Answer Is Not 0.52 m)

Section 2

A point charge has a charge of 2.50×10⁻¹¹ C .

Part A

At what distance from the point charge is the electric potential 84.0 V ? Take the potential to be zero at an infinite distance from the charge.

d = ___ m

Part B

At what distance from the point charge is the electric potential 25.0 V ? Take the potential to be zero at an infinite distance from the charge.

d = ___ m

A ball is tossed from an upper-story window of a building. The ball is given an initial velocity of 7.60 m/s at an angle of 15.0

Describe rotameter-type flowmeters, explain how they work, and compare them with

Venturi flowmeters

Two balls (solid spheres) have the same radius and the same rotational kinetic energy. If the ratio of their masses is

=

, what is the ratio of their angular velocities?

nvm

A mass m = 12 kg rests on a frictionless table and accelerated by a spring with spring constant k = 5249 N/m. The floor is frictionless except for a rough patch. For this rough path, the coefficient of friction is μ_k = 0.49. The mass leaves the spring at a speed v = 3.2 m/s.

A)How much work is done by the spring as it accelerates the mass?
B)How far was the spring stretched from its unstreched length?
C)

The mass is measured to leave the rough spot with a final speed v_f = 1.9 m/s.

How much work is done by friction as the mass crosses the rough spot?
D)What is the length of the rough spot?
E)In a new scenario, the block only makes it (exactly) half-way through the rough spot. How far was the spring compressed from its unstretched length?
F)In this new scenario, what would the coefficient of friction of the rough patch need to be changed to in order for the block to just barely make it through the rough patch?

a 2kg mass lying at rest at the origin is subjected to a force of 10 N directed along the positive X-axis and another force of 10 N along the positive y-axis. How far from the origin will the mass be in 5 seconds?

You have been called to testify as an expert witness in a trial involving a head-on collision. Car A weighs 1515 lb and was traveling eastward. Car B weighs 1125 lb and was traveling westward at 41.0 mph. The cars locked bumpers and slid eastward with their wheels locked for 21.5 ft before stopping. You have measured the coefficient of kinetic friction between the tires and the pavement to be 0.750. How fast (in miles per hour) was car A traveling just before the collision? (This problem uses English units because they would be used in a U.S. legal proceeding.)

A mountain climber jumps a 3.2m -wide crevasse by leaping horizontally with a speed of 7.1m/s . If the climber's direction of motion on landing is -45?, what is the height difference between the two sides of the crevasse?

The position of a 2.75

A rock is suspended by a light string. When the rock is in air, the tension in the string is 45.0 N . When the rock is totally immersed in water, the tension is 29.2 N . When the rock is totally immersed in an unknown liquid, the tension is 21.0 N .

What is the density of the unknown liquid?

A luge and its rider, with a total mass of 84 kg, emerge from a downhill track onto a horizontal straight track with an initial speed of 33 m/s. If a force slows them to a stop at a constant rate of 1.1 m/s2, (a) what magnitude F is required for the force, (b) what distance d do they travel while slowing, and (c) what work W is done on them by the force? What are (d)F, (e)d, and (f)W if they, instead, slow at 2.2 m/s2?

When the three blocks in the figure below are released from rest, they accelerate with a magnitude of 0.680 m/s2. Block 1 has mass M, block 2 has 3M, and block 3 has 3M. What is the coefficient of kinetic friction between block 2 and the table?