Could someone me with this kinematics question? :

a swimmer heads directly across a river, swimming at 1.6 m/s relative to the water. she
arrives at a point 40 m downstream from the point directly across the river, which is 80 m
wide.

a) what is the speed of the river current?

b) what is the swimmer's speed relative to the shore?

c) in what direction should the swimmer head to arrive at the point directly opposite her
starting point?

d) how long would it take to cross the river swimming in the direction found in (c)?

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?

Anonzero net force acts on a particle and does work. which one of the following statements is true? the kinetic energy of the particle changes, but the speed of the particle does not change. the kinetic energy of the particle does not change, but the speed of the particle does change. the kinetic energy of the particle changes, but the velocity of the particle does not change. the kinetic energy and the speed of the particle change, but the velocity of the particle does not change. the kinetic energy, speed, and velocity of the particle change.

Calculate a pendulums frequency of oscillation (in hz) if the pendulum completes one cycle in 0.5s.