Suggest a form of renewable energy that could be used to power an electric ticket machine that only needs to work during daylight hours

A bridge is 500m long. A 100m long train crosses it at a speed of 30m/s. Find the time taken by the train to cross it.

5. The group number of the carbon family is: a. 1 b. 2 C. 3 d. 4

When an electroscope is charged, its two leaves repel each other and remain at an angle. What balances the electric force of repulsion so that the leaves don't separate further?

Two positive charges of 2.8 x 10^-6 are separated by 0.50m. What force exists between the two charges?

A box slides down a 30.0° ramp with an acceleration of 1.20 m/s^2. Determine the coefficient of kinetic friction between the box and the ramp.

Why does the percentage of water vapor vary?

A situation that restricts something

Why is the sky blue all the time

Where did the rotational kinetic energy of the earth come from?

What is the mass in kg of a leopard in a tree if the tree branch is 36 m up and the leopard's gravitational potential energy is 29988 J?