A student of mass M stands on a newton scale in an elevator. At the instant the elevator has a upward acceleration of 1.50 m/s^2? and an downward velocity of 3.0 m/s, the scale reads approximately:
A)12.8M Newtons
B)11.3M Newtons
C)8.3M Newtons
D)6.8M Newtons

Identical marbles are released from the same height on each of the following four frictionless ramps . compare the speed of the marbles at the end of each ramp. explain your reasoning

Red light strikes a metal surface and electrons are ejected. if violet light is now used with a 10% greater intensity, what will happen to the ejection rate (number of ejected electrons per second) and the maximum energy of the electrons? a) greater ejection rate; same maximum energyb) same ejection rate; greater maximum energyc) greater ejection rate; greater maximum energyd) same ejection rate; same maximum energye) none of the above answers are correct

Find the dimensions and area of the largest rectangle that can be inscribed in the upper half of the ellipse. (give your answers in terms of a and b. enter the dimensions as a comma-separated list.)