Why isn't Earth a closed system

How did cavemen evolve into humans like what we have today what was the cause of it

Determine the x intervept of the line from equation 8x - 5y = - 11

If a polythene rod is rubbed with a dry cloth, what kind of charge would it gain? A) positive, due to extra protons. B) positive, due to electrons lost. B) negative, due to protons lost. D) negative, due to extra electrons.

An inductor is connected in series to a fully charged capacitor. which of the following statements are true?

If we decrease the amount of force, and keep all other factors the same, what will happen to the amount of work? The amount of work will go down because the distance will decrease. The amount of work will go up because the distance will decrease.

Light from the sun travels through space to Earth's atmosphere. Which will light waves do when they move from empty space into matter made up of different gases? A. move at the same speed B. move faster as they transmit C. slow down and refract D.

A 12.5 kg box sliding on a frictionless flat surface tuns into a fixed spring which compresses at a distance x = 14.1 cm. the spring constant is 94.5 kN/m Find the initial speed of the box

An earth scientist who studies hydrosphere

In 1991 four English teenagers built an eletric car that could attain a speed of 30.0m/s. Suppose it takes 8.0s for this car to accelerate from 18.0m/s to 30.0m/s. What is the magnitude of the car's acceleration?

A capacitor with a capacitance of 490 μf is charged to a voltage of 260 v. then a wire is connected between the plates. how many joules of thermal energy are produced as the capacitor