4a. three of your friends are all sitting on one end of a seesaw. the combined weight is 275 n. the length from the fulcrum to your friends is 2.5 m. the rest of the seesaw (from the fulcrum to you) is 4.5 m. what is the ma? what effort force is needed to lift your friends?

The motor m applies a time-varying force of f (200 t) n, where t is in seconds. box b with mass 200 kg starts from rest, and the coefficients of kinetic and static friction are 0.2 and us 0.3 the acceleration due to gravity is g 9.8 m/s2 b 300 a) find the time ' when the box starts to move. b) calculate the speed of the crate at 3 s c) calculate the power delivered by the motor at t 3 s

Acold front traveling southeast collided with a warm front traveling northwest the following map shows the weather on monday the day the two fronts collided which of these describes the weather forecast for mississippi on tuesday and wednesday

Awelder using a tank of volume 7.50×10^-2 m^3 fills it with oxygen (with a molar mass of 32.0 g/mol ) at a gauge pressure of 3.30×10^5 pa and temperature of 37.1 ∘c. the tank has a small leak, and in time some of the oxygen leaks out. on a day when the temperature is 23.1 ∘c, the gauge pressure of the oxygen in the tank is 2.00×10^5 pa . a) find the initial mass of oxygen. b) find the mass of oxygen that has leaked out.