True or false

Lightning happens because of the release of static electricity.

What type of friction acts when a snooker ball is moving on a pool table. a) Static friction b) Sliding friction c) Rolling friction d) None of these

A 0.145-kg baseball is pitched at 42 m/s. the batter hits it horizontally to the pitcher at 58 m/s. find the change in momentum of the ball.

Where do most of the visible electromagnetic waves on Earth come from?

Why is it that the weight of an object weighing 1N air, weighs more when immersed in water?

describe a kind of renewable energy that you could use in your home, and explain why it is a good choice.

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?