An object of mass m = 2.9 g and charge q = +42 µc is attached to a string and placed in a uniform electric field that is inclined at an angle of 30.0° with the horizontal. the object is in static equilibrium when the string is horizontal.
a) find the magnitude of the electric field. b) find the tension in the string. i know a is -mg + sin 30 * qe =0 but i don't know how to solve for it

It's a snowy day and you're pulling a friend along a level road on a sled. you've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. you've been walking at a steady 1.5m/s, and the rope pulls up on the sled at a 32 ∘ angle. you estimate that the mass of the sled, with your friend on it, is 65 kg and that you're pulling with a force of 80 n .