Abox (m = 20 kg) is sliding on a horizontal surface. it is connected to a massless hook by a light string passing over a massless pulley wheel. the coefficients of friction between the box and the surface are 0.80 (static) and 0.30 (kinetic). if 15 kg (in total) are placed on the hook, calculate the acceleration of the box.

Truck traveling west on the highway experiences an acceleration to the east. what could be the cause of this acceleration

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

Why are graphs useful when interpreting data