A hollow plastic sphere is held below the surface of a freshwater lake by a cord anchored to the bottom of the lake. The sphere has a volume of 0.700m3 and the tension in the cord is 840N. What is the mass of the sphere?

1) Using one of your heights and times from when the object was released to when the object hits the floor, calculate g. (This is an experimental value of g)

2) Using all of you height data points, figure out how to make a linear graph of height and time. Determine the slope of the graph. This is related to your second experimental value of g. Determine your second experimental value of g.

3) compare both your experimental values of g to the theoritcal value.

4) What is the percentage difference btween your experimetal values of g and the accepted value, 9.81m/s2 ?

5) How do you account fo this difference?

6) Does the theoritcal value for g fall within the final error range (the uncertainity) of your experimental value?

7) Explain with the primary limitation on your data and how it can be corrected. What factor in the experiment had the biggest effect on collecting valid data and how would you make the experiment more accurate?

please answer all questions and show work

Correct asnwer for 5 star rating.

Suppose that you release a small ball from rest at a depth of 0.520 m below the surface in a pool of water. If the density of the ball is 0.285 that of water and if the drag force on the ball from the water is negligible, how high above the water surface will the ball shoot as it emerges from the water? (Neglect any transfer of energy to the splashing and waves produced by the emerging ball.)
INCLUDE UNITS ON ANSWER

Cesium-124 has a half-life of 30.9 s.

a) How many Cs-124 nuclei are in 19 micrograms of said isotope?

b) How about after 2.4 min?

c) How strong is its activity then?

d) After which time has activity dropped below 1.0 Bq?

What is fluorescence and how is it generated? explain absorption and emission

The two wires carry current i₁ and i₂, respectively, with positive current to the right. The charge q is positive and has velocity v to the right.

True False  If i₁ is greater than i₂, then the force on q is north.
True False  If v = 0, then the force on q is zero.
True False  If i₂ = - i₁ then the force on q equals zero.
True False  If i₂ = 0 and i₁ is greater than zero, then the force on q points into the page.
True False  If i₁ = 0 and i₂ is greater than zero then the force on q is south.
True False  If i₂ = 0 and i₁ is greater than zero, then the magnetic field near charge q points out of the page.
True False  If i₁ = i₂, then the wires are attracted to each other.

8.) When you look at most people

What is the maximum velocity of electrons ejected from a material by 90 nm photons, if they are bound to the material by 4.73 eV?

The figure above shows a portion of the trajectory of a ball traveling through the air. Arrows indicate its momentum at several locations. At these locations, the ball's momentum is: B = ‹ 3.18, 2.88, 0 › kg·m/s C = ‹ 2.7, 1.02, 0 › kg·m/s D = ‹ 2.39, ?0.52, 0 › kg·m/s E = ‹ 2.12, ?1.88, 0 › kg·m/s (a) Which of the diagrams below correctly shows the graphical relationship between B , C , and ? , the change in the ball's momentum as it moves from location B to C? 1 3 2 (b) What is the change in the ball's momentum as it moves from location B to C? ? = kg·m/s What is the change in the ball's momentum as it moves from location C to D? ? = kg·m/s What is the change in the ball's momentum as it moves from location D to E? ? = kg·m/s (c) Between which two locations is the magnitude of the change in momentum greatest? B to C C to D D to E (d) What is this greatest magnitude of the change in the ball's momentum? ? max = kg·m/s

. Charge q1= 1.80*10-8 C is placed at the origin O. Charge q2 = -7.20*10-8 C is placed at point A ( x =0.180 m) as shown in the figures. a.

A charge q3 = 2.5 *10^-8 C is placed at point B ( x = 0.0900 m) as shown in fig.a. Determine the net force F3 exerted on charge q3 by q1 and q2. Give your answer unit vector notation. b. The charge q3 is now placed at point C ( x = 0.270 m) as shown in fig.b. Determine the net force F3 exerted on charge q3 by q1 and q2. Give your answer unit vector notation. c. Find the coordinate xD of a point D on the negative x-axis for which of the net force F3 exerted on q3 by q2 and q1 is zero. Use fig.c. q1 q 3 q2 x fig.a O B A.

1.  Two 3 kg physical science textbooks on a book shelf are separated by 0.25 m. What is the force of gravitational attraction between the books?   

2. What is the force of gravity between two 1000 kg cars separated by a distance of 20 m on a highway?

3. Using the force, calculated in # 2 above, and the weight of the car, calculate:     

Force (from #2) divided by the weight of car   

4. How would the force of gravity between two masses be affected if the separation distance between them is doubled?

5. How would the force of gravity between two masses be affected if the separation distance between them is decreased by one-half?

6. The separation distance between two 2.0 kg masses is decreased by two-thirds. How is the gravitational force between them affected?

7. A man has a mass of 150 kg. What does he weigh on earth expressed in N?

8. If the gravitation constant on the moon, gm is one-sixth that on the earth, how much does the man in # 7 weigh on the moon?

9. An astronaut on the moon places a package on a scale and finds it weight to be 15 N. What would the package weigh on earth?

10. What is the package's mass on the moon?

A 2,200-kg car is moving down a road with a slope (grade) of 14% at a constant speed of 11 m/s. What is the direction and magnitude of the frictional force?
(define positive in the forward direction, i.e., down the slope)?

A 2,282-kg car is moving up a road with a slope (grade) of 10% at a constant speed of 12 m/s. What is the direction and magnitude of the frictional force?
(define positive in the forward direction, i.e., up the slope)?

On a Saturday morning, pickup trucks and sport utility vehicles carrying garbage to the town dump form a nearly steady procession on a country road, all traveling at21.8 m/s. From one direction, two trucks arrive at the dump every two minutes. A bicyclist is also traveling toward the dump, at 4.12 m/s.

(a) With what frequency do the trucks pass him?
?min^-1
(b) A hill does not slow down the trucks, but makes the out-of-shape cyclist's speed drop to 1.56 m/s. How often do noisy, smelly, inefficient, garbage-dipping, roadhogging trucks whiz past him now?
? min^-1

What is the difference between entropy, enthalpy, and heat transfer?

A 145 g mass attached to a horizontal spring oscillates at a frequency of 5.50 Hz. At t = 0s, the mass is at x = 6.60 cm and has v_x =− 35.0 cm/s.

Determine:

a) The maximum speed.

b) The maximum acceleration.

c) The total energy.

d) The position at t = 3.20 s.