Which of the following explains why a bicycle uses a lever?

reduces the effort force*I picked this one

increases the effort force

reduces the resistance force

increases the resistance force

A student allows the evaporating dish and the anhydrous salt for a long time on the lab bench. What will happen to the mass of the content of the evaporating dish as it cools and how could this be prevented? G

A sound wave has a frequency of 628 Hz in air and a wavelength of 0.49 m. What is the temperature of the air? Assume the velocity of sound at 0^◦C is 325 m/s. Answer in units of ◦C.

Density is calculated by dividing

A closed and elevated vertical cylindrical tank with diameter 2.00 m contains water to a depth of 0.800 m. A worker accidentally pokes a circular hole with diameter 0.0200 m in the bottom of the tank.

Suppose you have a balloon with a volume of 0.1 m3 and a temperature of 300 Kelvin. You leave the balloon in a car with the windows rolled up and the temperature rises to 315 degrees Kelvin. What is the new volume of the balloon?

A force produces power p by doing work w in a time t. what power will be produced by a force that does six times as much work in half as much time?

A batter hits a baseball with a bat. The bat exerts a force on the ball. Does the ball exert a force on the bat?

In a nuclear power plant, the temperature of the water in the reactor is above 100°C because of what?

Determine the total mechanical energy of a 250 g baseball if it has a velocity of 30 m/s when it leaves the pitcher's hand 1.2m above the ground.

When distances were carefully measured from Earth to globular clusters above and below the Milky Way plane (where our view of them is not obscured by interstellar dust and gas), their distribution was found to be