Explain why and how theories may be changed or replaced over time.

1. Suppose that you have a mass of 45.7 kg and are standing on frictionless roller skates. Someone then throws you a 2.50 kg mass with a velocity of 14.5 m/s and you catch it. What will be your resultant velocity? (0.75 m/s)

Which is an example of negative acceleration? a snowboarder who increases speed when traveling downhill a biker who maintains a constant speed through a race a skateboarder who reduces speed when moving up a hill a runner who fluctuates speed by

The force required to turn a screwdriver can be reduced by?

Which term is the common name of the group whose members are characterized by endoskeleton and a unique water vascular system? brachiopods echinoderms tunicates medusas

A truck travels 90 m north then 30 m south then 40 m north what's the distance and displacement

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?