How do scientist learn about stars and galaxies even tough humans have never been there?

What factors affect the upthrust exerted by the fluid on any object immersed on it?

What is the weight of a 2.00-kilogram object on the surface of Earth? (1) 4.91 N (3) 9.81 N (2) 2.00 N (4) 19.6 N

How does the electric force between two charged particles change if particle's charge is reduced by a factor of 3?

A zero-order reaction has a constant rate of 2.30*10-4 M/s. If after 80.0 seconds the concentration has dropped to 1.50*10-2 M, what was the initial concentration?

Use the small-angle formula to calculate the angular diameter of Earth as seen from the Moon. (Note: The linear diameter of Earth is; the average distance between the Moon and Earth is; the small-angle formula is.)

4. How far does a car travel in 90 seconds if it is traveling at a speed of 55 m/s?

Total energy input is 1400 and my efficiency is 80% so what is the useful energy output in jules?

What is the force of gravity acting on a 2000-kg spacecraft when it orbits two Earth radii from the Earth's center (that is a distance r=6380 km above the Earth's Surface. The mass of the Earth is 5.98 x 1024 kg.

An LC circuit has a 6.00 mH inductor. The current has its maximum value of 0.570 A at t = 0s. A short time later the capacitor reaches its maximum potential difference of 66.0 V. What is the value of the capacitance?

The first law of thermodynamics states that ΔE = Q - W. Is this also a statement of the principle of conservation of energy? Yes, the heat added and the change in internal energy of the gas equal the work done by the piston.