Explain why an experiment should test only one variable at a time

Why can the volume of a sample of plasma change when the substance is moved from one container to another? Plasma is made of charged ions and electrons, so they interact differently in different places.

A 24 volt doorbell carries a current of 1/2 ampere. Calculate the resistance in the bell 1. 2. 3.

Plants that can live in water soaked soil are able to survive in the what ecosystem?

Determine the heat given off to the surroundings when 9.0 g of aluminum reacts according to the equation 2al + fe2o3 → al2o3 + 2fe, δh°rxn = - 849 kj/mol.

A car (m = 2000 kg) is going around an unbanked curve at the recommended speed of 11m/s (24.6 MPH). (a) If the radius of the curvature of the path is 25m and the coefficient of static friction between the rubber tires and the road is µs = 0.

What is the weight of a 65 kg astronaut on mars?

When lava cools, what type of Rock forms?

A uniformly charged conducting sphere of 1.1 m diameter has a surface charge density of 6.2 µC/m2. (a) Find the net charge on the sphere. (b) What is the total electric flux leaving the surface of the sphere?

A blow-dryer and a vacuum cleaner each operate with a voltage of 120 V. The current rating of the blow-dryer is 12 A, while that of the vacuum cleaner is 5.7 A. Determine the power consumed by (a) the blow-dryer and (b) the vacuum cleaner.

4. A 40 kg child and a 30 kg child want to balance themselves on a 4 meter, 50 kilogramn see-saw. Where should the fulcrum be placed?