Could someone please help and explain

Aman tries to push a box of mass 4 kg with a force of 5 n but the box remains stationary if the coefficient of static friction is 0.45, what is the value of the maximum force of friction?

When someone slams her books on a table the kinect energy is transferred into vibrations that travel to your ears as sound waves which statement describes the movement of those waves

Steelhead trout migrate up stream to spawn. occasionally they need to leap up small waterfalls to continue their journey. fortunately, steelhead are remarkable jumpers, capable of leaving the water at a speed of 8.0 m/s. a. what is the maximum height a steelhead trout can jump? b. leaving the water at 8.0 m/s, the trout lands on top of the water fall 1.8 m high. how long was it in the air?