Master Physics with Fun Quizzes & Brain Teasers!

An ideal (non-viscous, incompressible) fluid flows through a horizontal pipe. The fluid density is 900 kg/m3. Initially, the pipe has a diameter of 0.7 cm and the fluid flows at a speed of 9 m/s at a pressure of 13,000 N/m2. Then, the pipe widens to a diameter of 2.1 cm. What is the speed of the fluid in the wider section of the pipe, in units of m/s
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Desde lo alto de un acantilado de 140 m, se lanza verticalmente un objeto hacia abajo con velocidad de 3m/s. Entonces la magnitud del desplazamiento que ejecuta en t = 3s es: (use g = 10 m/s2)
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A 0.47-kg block is hung from and stretches a spring that is attached to the ceiling. A second block is attached to the first one, and the amount that the spring stretches from its unstretched length triples. What is the mass of the second block
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The initial kinetic energy imparted to a 0.25 kg bullet is 1066 J. The acceleration of gravity is 9.81 m/s 2 . Neglecting air resistance, find the range of this projectile when it is fired at an angle such that the range equals the maximum height attained. Answer in units of km.
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A 20-kg object sitting at rest is struck elastically in a head-on collision with a 10-kg object initially moving at 3.0 m/s. Find the final velocity of the 10-kg object after the collision.
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What happens during a chemical reaction ?
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The formation of a product in the reaction is based on what
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A car manufacturer wants to change its cars design to increase the cars acceleration. Which changes should the engineers consider making to the design?
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A soccer ball is released from rest at the top of a grassy incline. After 2.2 seconds, the ball travels 22 meters. One second later, the ball reaches the bottom of the incline. (Assume that the acceleration was constant.) How long was the incline
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A wire carries a current of 4 A travelling to the left (-x direction). It is placed in a constant magnetic field of magnitude 0.05 T, pointing upward ( z direction). a. If 25 cm of the wire is in the magnetic field, what is the force on the current
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We have compared the Terrestrial Planets and the Giant or Jovian Planets, but when we look at the 4 Giant Planets we can see that they can be paired into Jupiter and Saturn vs. Uranus and Neptune. (2 pts.) (1a) Explain 3 similarities shared by all 4 giant planets.
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Points P and Q are separated by a distance of 0.10 m in a uniform electric field. The potential difference between points P and Q is 55 V. What is the magnitude of the electric field?
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9/10 in percents. Examples please, at least 2.
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State the requirements to perform a goodness-of-fit test. Choose the correct answer below. Select all that apply. A. at least 90% of expected frequencies greater than or equals10 B. at least 80% of expected frequencies greater than or equals10 C. all expected frequenciesgreater than or equals5 D. at least 80% of expected frequencies greater than or equals5 E. at least 90% of expected frequencies greater than or equals5 F. all expected frequenciesgreater than or equals1
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Suppose you are chatting with your friend, who lives on the moon. He tells you he has just won a Newton of gold in a contest. Excitedly, you tell him that you entered the Earth version of the same contest and also won a Newton of gold. Who is richer
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One uniform ladder of mass 30 kg and 10 m long rests against a frictionless vertical wall and makes an angle of 60o with the floor. A man weighing 700 N could climb up to 7.0 m before slipping. What is the coefficient of static friction between the floor and the ladder
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Which shows an example of a single replacement reaction
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A coaxial cable consists of a thin insulated straight wire carrying a current of 2.00 A surrounded by a cylindrical conductor carrying a current of 3.50 A in the opposite direction. The cylindrical conductor has a radius of 0.420 cm. What is the magnitude of the magnetic field outside of the cylindrical conductor 2.00 cm from the central wire
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Ideal incompressible water is flowing in a drainage channel of rectangular cross-section. At one point, the width of the channel is 12 m, the depth of water is 6.0 m, and the speed of the flow is 2.5 m/s. At a point downstream, the width has narrowed to 9.0 m, and the depth of water is 8.0 m. What is the speed of the flow at the second point
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g You have a suction cup that creates a circular region of low pressure with a 30 mm diameter. It holds the pressure to 78 % of atmospheric pressure. What "holding force" does the suction cup generate in N
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Which data set has the largest standard deviation?A. 20, 21, 23, 19, 19, 20, 20OB. 1.6,3, 15, 4, 12, 8O C. 3.4.3.4.3.4.3O D. 12. 14, 13, 14, 12, 13, 12
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A box of mass 45 kg is at rest on a horizontal frictionless surface. A constant horizontal force F then acts on the box and accelerates it to the right. It is observed that it takes the box 7.5 seconds to travel 40 meters. What is the magnitude of the force
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You throw a baseball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down. A) The work is positive on the way up and positive on the way down. B) The work is positive on the way up and negative on the way down. C) The work is negative on the way up and positive on the way down. D) The work is negative on the way up and on the way down because gravity is always
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His eyes are 1.85 m above the floor, and the top of his head is 0.15 m higher. Find the height above the floor of the top and bottom of the smallest mirror in which he can see both the top of his head and his feet.
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