A child plays with a black ball. Explain why the ball looks black

While carrying a heavy box up the stairs, you set the box on a step and rest. then you pick up the box and carry it to the top of the stairs. describe these actions in terms of balanced and unbalanced forces acting on the box.

If frequency goes up, what happens to wavelength? does it get shorter or longer?

What’s the kinetic energy of the object? use . erica is competing in the shot put event at a track meet. she hurls a shot with a mass of 4 kilograms at a speed of 9 meters/second. the shot’s kinetic energy is joules.