What do stars begin as

If the work put into a lever is 25.0 joules and the work done by the lever is 20.0 joules, what is the efficiency of the lever?

A device having a constant resistance operates at a voltage of 100 V. If the voltage supplied to the device increases by 10 percent, how does this affect the power used by the device relative to the power consumption at 100 V?

How much time does it take George to travel 240 M at a speed of 8 m per second?

A ball is dropped from a cliff that is 256 feet high. The height of the ball (in feet) after t seconds is given by the formula h (t) = 256 - 16t^2. How many seconds (to the nearest tenth) will it take for the ball to hit the ground? A. 4096 sec B.

What mechanism is most responsible for generating the internal heat of Io that drives its volcanic activity?

A projectile is launched over a horizontal surface in such a manner that its maximum height is 3/5 of its horizontal range. Determine the launch angle.

Two identical capacitors are arranged in a circuit. What is the ratio of the equivalent capacitance of the circuit when the capacitors are in series to that when they are in parallel?

A car's position in relation to time is plotted on the graph. What is the car's average velocity for segment C? A) - 4 m/s B) - 0.25 m/s C) 0.25 m/s D) 4 m/s

What percent of my Iodine-131 sample will be left after 7 half-lives?

A 58.0 kg snow skier is on the top of 351 m high hill. After she has gone down a vertical distance of 142 m, what is her mechanical energy? Explain your answer (CER) !