Why were Aristotle's and Ptolemy's models were accepted for more than a thousand years in spite of being completely incorrect?

If the cross-sectional area of a wire is decreased while all other factors remain the same, how will the resistance change? A. It will increase B. It will decrease. C. It will go to zero. D. The cross-sectional area does not affect the resistance.

An airplane flies with a constant speed of 800km/h. How far can it travel in 2 hours?

Air enters a horizontal, well-insulated nozzle operating at steady state at 12 bar, 500 K, with a velocity of 50 m/s and exits at 7 bar, 440 K. The mass flow rate is 1 kg/s.

A soccer player swings his leg forward to kick the ball. If his leg has a moment of inertia of 0.9 kg m2, and is initially at rest, how much torque must he generate with his hip flexor muscle in order to reach an angular velocity of - 8 rad/s in 0.

Whats the origin of all stars? a) supernova b) dwarfs c) protostars d) nebulae

Which of the following elements is the most reactive? Beryllium Calcium Magnesium Barium

A flash of white light containing all the colors of the visible spectrum in air shines straight down on the surface of a pool.

A car accelerates uniformly from 0 to 15m/s in 5 s. Calculate acceleration.

Which device would a sleep researcher use to monitor a sleeping person's brain waves?

An experiment is performed to obtain the value of a physical property. If the true (i. e., correct) value of the property is 50 and the measured (i. e., experimental) value is 32, the percent error of the experimental result is: