of oxygen (O2) contained in BIFs is equivalent to 6.6% of the oxygen present in the modern atmosphere. This is quite impressive given that the atmosphere during Archaean and early Proterozoic times was largely devoid of oxygen! Therefore, this reflects the photosynthetic efficiency of the early biosphere, coupled with its operation over long periods of time. Knowing that the mass of the modern atmosphere is 5.01×1018 kg, of which 21% is oxygen, what is the mass (in kilograms) of oxygen contained within BIFs?

Q: Suppose that À = 2i + j, B= i– 4j + k, and = j+k. ... What is Á· (B x Č), A A. -2 в) в. -2 k с) с.-1...

A: The correct answer is option (c) i.e -11

Q: 1. Two balls of masses MĄ = 45 g and mB = 65 g, are suspended as shown below. The lighter ball is pu...

A:

Q: Question 2: A snowboarder starts from rest at the top of a double black diamond hill. As she rides d...

A:

Q: 2. In the circuit of Fig. 2 calculate: a) Total Capacitance b) Total charge of the network c) Voltag...

A:

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A: Figure demonstrating the given system

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A: Motion of projectile can be divided into x component and y component. 

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A:

Q: A block is pulled along a rough level surface at constant speed by the force P. The figure shows the...

A:

Q: • Part A The RC circuit on the figure has R = 6.8 kſN and C = 4.0 µF . The capacitor is at voltage V...

A: In this question we have to find the time taken to discharge the capacitor. Please give positive fee...

Q: work done by 0.30kg  of air in a isothermal expansion from p1=1490 kpa to p2=567kpa at 655 k.

A: Given Mass = 0.3 kg = 300 g  Initial pressure P1 =1490 kPa  Final pressure = 567 kPa  Temperature T ...

Q: In a tug-of-war, each man on a 5-man team pulls with an average force of 500 N. What is the tension ...

A: In this case each team pulls with a force of 2500 N because 500x5= 2500 N  The rope pulls back with ...

Q: A speed boat pulls a water-skier (with a mass of 100 kg) at a steady speed by a rope at 15 degrees a...

A:

Q: 3. A conducting rod of length ( = 35.0 cm is free to slide on two parallel conducting bars as shown ...

A:

Q: Which of the following statement is/are true? (A) The acceleration in free fall at the maximum heigh...

A:

Q: An alpha particle (consisting of two protons and two neutrons), traveling at a speed of v = 1.4 x 10...

A: Given value--- speed = 1.4 × 105 m/s. magnetic field = 1.8 T. We have to find--- Part (b)  In uni...

Q: A flat square with sides 18 cm is placed in a uniform electric field of magnitude 5784 N/C. What is ...

A:

Q: The vector A has magnitude of 5.0 and a direction of 14 , while B has a magnitude of 4.0 and a direc...

A: The below shows diagram showing the addition of vectors A and B.

Q: There are three charges interacting to one another. Q2 which has a value of +3.52 nC is at the negat...

A: Q2 = +3.52 nC Q3 = -7.80 nC at origin Q1 = 6.01 nC d13 = 0.45 m d12 = 0.8 m   

Q: TRUE OR FALSE. If a body X, with a positive charge, is placed in contact with another body Y (initia...

A: Let the charge carried by positively charged body X = Q The charge on body Y = 0 (neutral)   

Q: 92 88 84 80 76 (73.2, 73 6) 72 68 64 60 56 52 48 44 40 36 32 28 24 20 16 12 4 o 0.0, 0)- 10 20 30 40...

A:

Q: Consider a small sphere (an actual sphere, not a Gaussian surface) of radius R = 0.1 m that is charg...

A:

Q: Suppose that À = 2i + j, B = i- 4j + k, and Ĉ = j+k. What is the magnitude of the vector 2Ã – B + Ĉ;...

A:

Q: A transformer has a turns ratio of 2.5:1 the primary voltage is 208V what is the voltage of the seco...

A:

Q: Technetium-99m is a radioactive isotope with a half-life of 6 hours. If a sample of was originally 1...

A:

Q: The diagram below presents the position and elapsed time of a motorbike that starts from rest and ac...

A: Write the expression for the average velocity. Here, x represents the displacement and t represents...

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A:

Q: Diagram the forces acting on the crate.: B.) Pulling a crate at an angle A.) Pulling a crate 30°

A: (A) Here, mainly 4 forces acting on the system. (1) Weight of crate ( downwards)  (2) Normal reactio...

Q: | = ??? Battery E = 18 V Lamp R = 3 0 | = ???

A:

Q: 22. Tied to point A by a string. Moving In a horizontal circle at constant speed. Not resling on a s...

A:

Q: 1. Two cars, A and B, are travelling in the same direction, although car A is 182 m behind car B. Th...

A:

Q: Question 19 Given two vectors: M = -3î + 6j – 5k and N = -2î + 3j + k The expression 2Ñ - Mis: A No ...

A: M→ = -3i^ + 6j^ -5k^N→ = -2i^ + 3j^ + k^To find : 2N→ - M→  

Q: Ã = 2i + j, B = i- 4j + k, and = j+k. What is A· (B x Ĉ), A -10i -j B 10i + j -10 -11

A:

Q: Problem 2: An object weighing 5N has an inifial velocity of 180 km per hour. If the coefficient of k...

A: weight of object = mg = 5 N mass = m = 5g=59.8=0.51 kg initial velocity = V0= 180 km/h = 180 x 518 =...

Q: An object is moving along a straight line in the positive x direction. The graph shows its position ...

A:

Q: An ant has projecting a speed of 1 m/min. Calculate the distance traveled by the ant at the end of 1...

A:

Q: 27. Resting against the frictionless inside wall of a cone rotating about its vertical axis at const...

A: Part (27): Given: The surface is frictionless. The object is moving at a constant speed.

Q: The capacitance of a spherical capacitor with inner radius a and outer radius b is proportional to: ...

A:

Q: If gravity pulls you down toward the center of Earth with a force of 500 N, how much upward force do...

A: From Newton's 3rd laws of motion, to every action , there is equal and opposite reaction.  

Q: n which one of the following situations does the car have a westward acceleration? A The car travels...

A: Acceleration is the rate of change of velocity.

Q: Suppose that Å = 2i + j, B = i- 4j + k, and Ĉ = j+k. What is the direction of vector A ? A 26.6 E of...

A: Given: A→=2i+jB→=i-4j+kC→=j+k

Q: A lens has one concave surface with a radius of curvature RA = 6.0 cm and one convex surface with ra...

A: Here R1= radius of curvature of first lens= -6 cm = -0.06 m ( as concave lens) R2= +8cm = 0.08 m .

Q: runaway dog walks 0.64 km due north. He then runs due west to a hot dog stand. If the magnitude of o...

A:

Q: Question 21 If gravity pulls you down toward the center of Earth with a force of 500 N, how much upw...

A: Given: Normal Force = 500 N  

Q: Sarah Robredo has a pingpong ball. She fastened it to a rope and is swung in a vertical circle. What...

A:

Q: A baseball is thrown at an angle of 40.0° above the horizontal. The horizontal component of the base...

A:

Q: The x and y components of a displacement vector are -3.00 m and +4.00 m, respectively. What angle do...

A:

Q: A speed boat pulls a water-skier (with a mass of 100 kg) at a steady speed by a rope at 15 degrees a...

A:

Q: A mass hangs on the end of a massless rope. The pendulum is held horizontal and released from rest. ...

A: we have the situation

Q: TRUE OR FALSE. If a body X, with a positive charge, is placed in contact with another body Y (initia...

A: According to question we need to find that the given statement is true or false .

Q: If the coefficient of kinetic friction, Uk, between the block and the surface is 0.30 and the magnit...

A: Weight = friction force / uk

Half Life

The concept of Half Life has numerous practical applications some of them includes figuring out the effective drug dosage to finding out when a radioactive becomes safe to use. If you look for a career in Nuclear Physics you will need this concept.