A spring has a natural length of 20cm. If a 25-N force is required to keep it stretched to a length of 30 cm, how much work is required to stretch it from 20 cm to 25 cm?

Theo was doing research to support the claim that exercise increases heart and lung health. He had 50 people do a rigorous exercise program. Each week, for six months, he tested their heart and respiratory rate.

Calculate the average speed of a car between 0 And 10 second give the unit

A 6,000-watt electric water heater is plugged into a 240-volt outlet and used for 0.75 hours. How much current runs through the water heater? 0.04 amps 19 amps 25 amps 33 amps

A ball sitting on the top of a table has potential energy but no kinetic energy. How do potential and kinetic energy change as the ball falls off the table to the floor? A. Its potential energy increases, and its kinetic energy decreases. B.

A particular star cluster contains stars all with the same apparent magnitude of + 4. Near the cluster (and at the same distance from the Earth) is a single star with an apparent magnitude of + 1.

For glass fragments to be individualized, what must be true? A. They must fit together B. They must have the same density C. They must look the same D. They must be the same color

In what way would a digital thermometer be preferable to those from a liquid-based thermometer? Digital thermometer readings are easier to use when performing calculations.

Why does the core of the sun contain more helium and less hydrogen than the surface of the sun?

What happens to a light ray passing through the center of a lens?

A spider crawling across a table leaps onto a magazine blocking its path. The initial velocity of the spider is 0.870 m/s at an angle of 35.0° above the table, and it lands on the magazine 0.0770s after leaving the table. Ignore air resistance.