How can you preveny friction from wearing things away?

Explain whether an object can have kinetic energy and potential energy at the same time

The bright light emission spectrums below are seen through a spectroscope. The unknown sample is a mixture of the observed gases. 5 rectangles labeled gas W, gas X, gas Y, gas Z and unknown sample.

Who developed the heliocentric model

A charge of + 3.0 mC is distributed uniformly along the circumference of a circle with a radius of 20 cm. How much external energy is required to bring a charge of 25mC from infinity to the center of the circle?

Convert 1 mm of hg into Pascal. Take density of hg = 13.6*10^3kg/m^3. g = 9.8m/s*s

Why are convection currents; why are they hotter and colder parts of earth

A swimmer is swimming to the left with a speed of 1.0 m/s when she starts to speed up with constant acceleration. The swimmer reaches a final speed of 2.5 m/s over a distance of 5.0 m. How long did the swimmer take to speed up to 2.

An archer defending a castle is on a 15.5 m high wall. He shoots an arrow straight down at 22.8 m/s. How much time does it take to reach the ground?

Four potential forces can act on the ball Which combination of forces will keep the ball in static equilibrium? The length of the arrows represents the magnitude of the force A and B A and C B and D 8. Cand D Submit Force, Mass, and Motion

The resultant of a 50N force acting on an object to the right and a 20N force acting on the object to the left is what