Physics

Lightning a. occurs when a positively charged cloud base induces a negative charge on the Earth's surface. b. travels most often from cloud to ground and cannot travel from cloud to cloud. c. may be accompanied by the sound of explosively expanding hot air, called thunder. d. involves a conductive path or leader of positive ions from cloud to ground.
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A force of 1000N is used to kick a football of mass 0.8kg find the velocity with which the ball moves if it takes 0.8 sec to be kicked.
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In a hydrogen atom, the electric force is the centripetal force. Determine the speed of an electron in orbit around a proton if the distance between them is 5.29 x 10^{-11} m. The mass of an electron is 9.11 x 10^-31 kg. (HINT: equate centripetal force and electric force)
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Which of the following is true about resistivity of any given metal? depends on its temperature. varies nearly linearly with temperature. has units of ohm-meter. A. II and III only B. I and II only C. I and III only D. I, II and III E. III only
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Un globo contiene 4 moles de un gas ideal con un volmen de 5,0 L. Si se agregan 8 moles adicionales del gas a presin y temperatura constantes, Cul ser el volumen final del globo? - Cul es la densidad (en g / L) de un gas con una masa molar de 60 g / mol a 0,75 atm y 27 C?
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why does apparent depth of different liquids vary
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b. Projectile on cliff (range)An object of mass 5 kg is projected at an angle of 25 to the horizontal with a speed of 22 ms-1 from the top of the cliff.The height of the cliff is 21 m. Take g, the acceleration due to gravity, to be 9.81 ms2How far horizontally (to 1 decimal place) from the base of the cliff does the object land?
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PLEASE HELP MAX POINTS AND BRAINLIEST!Look at the graph below.A graph is shown with Absolute magnitude shown on the y-axis and Surface temperature in degree Celsius shown on the x-axis. The Dwarf stars are shown along a slanting line from coordinates 30,000 and minus 3 to 10,000 and minus 4. The Main Sequence stars are shown along a slanting line from coordinates 20,000 and minus 2 to 2,000 and minus 6. The giants are shown along a line parallel to the x-axis from coordinates 5,000 and 2 to 2,000 and 3. The supergiants are shown along a line parallel to the x-axis from coordinates 7,500 and 4 to 2,500 and 4. Point A has coordinates 20,000 and minus 4. Point B has coordinates 2,500 and minus 4. Point C has coordinates 5,000 and 2. Point D has coordinates 7,000 and 4.Which of the following stars is most likely to be red?a. Star Ab. Star Bc. Star Cd. Star D
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A hydraulic vane pump has a real flow of 20 liters per minute, a pressure of 230 bar, a pump speed of 1400 rpm. Know that the input power is 10kW and the mechanical efficiency is 88%.a) Calculate the volumetric efficiency of the pumpb) Calculate the specific volume of the pump (cm/rev). Question 3 (2,5d): Design a pneumatic transmission system to control 02 single-acting cylinders, using 02 reversing valves 3/2 acting by push button, 02 throttle valves - one-way. Describe the working principle of the system.
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If H = + VE , THEN WHAT REACTION IT IS1) exothermic2) endothermic
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please answer fast..........
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out of solid and liquid which has more effect on gravitation
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balance the following equations: CUCO3+H2SO4- CUSO4+H2O+CO2
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A silicon solar cell behaves like a battery with a 0.46 V terminal voltage. Suppose that 1.0 W of light of wavelength 620 nm falls on a solar cell and that 50%% of the photons give their energy to charge carriers, creating a current. What is the solar cell's efficiency that is, what percentage of the energy incident on the cell is converted to electric energy?
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Define derived unit with example
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Consider a piston filled with 3 mols of an ideal gas, kept at a constant temperature 290 K. We slowly compress the gas starting at 2 m3 and ending at 1 m3. How much work do we need to do on the gas to perform this operation
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explain why resistors connected in parallel are called current dividers
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Cuando el pistn tiene un volumen de 2x10^-4 m^3, el gas en el pistn est a una presin de 150 kPa. El rea del pistn es 0.00133 m^2. Calcular la fuerza que el gas ejerce sobre el embolo del pistn.
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Two forces A and B act at a point. If their resultant is [given by] (B - A) in the direction of B, thenA. A and B are equalB. A is greater than BC. the angle between A and B is 0D. the angle between A and B is 90E. the angle between A and B is 180
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Which of the following is a form of mechanical energy?A. Chemical energyB. Gravitational potential energyC. Thermal energyD. Nuclear energy
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a.quuntlity.Answer the following questions.What is force? Write down its SI unit.b. Nameany five types of force.c.What is pulling force? Give any two examples.d. What is centripetal force? Give one example of centrifugal force.What is gravitational force? Give two examples.f. What is magnetic force? How is this force useful to us?
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En la siguiente expresin matemticas w=mg el peso w con relacin a se relaciona con la masa m en una proporcin a) Directamente proporcional b) Inversamente proporcional c) Es constante d) Ninguna de las anteriore
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What are the units for speed?O A. km/s2O B. m/s2O C. m/s2O D. m/s
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Write the dimension of a / b in the x = at + bt2. Where x is the distance and t is the time?
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