A student pulls a rope attached to a box of books and moves the box down the hall. The student pulls with a force of 185 N and an angle of 21.0° above the horizontal. The box has a mass of 45.0 kg and the coefficient of kinetic friction between the box and the floor is 0.27. Find the acceleration of the box. 1.2 m/s2
4.1 m/s2
2.8 m/s2
3.8 m/s2

Atriangle with equal sides of length 10 cm has -2.5-nc charged objects at each corner. part a determine the direction of the electrical force exerted on the object at the top corner due to the two objects at the horizontal base of the triangle. determine the direction of the electrical force exerted on the object at the top corner due to the two objects at the horizontal base of the triangle. horizontally rightward vertically downward vertically upward horizontally leftward

Emagnitude of the electrical force acting between a +2.4 ×  10–8  c charge and a +1.8 ×  10–6  c charge that are separated by 0.008 m is    n, rounded to the tenths place.

Why do atoms emit energy of only specific wavelengths