One of the ways that scientists determine the distance between Earth and other objects in space is to send light waves toward an object and measure how long it takes for the waves to bounce back. If a scientist sends light waves to four different objects in space, which of the following will take the longest to bounce the wave back to Earth? a star in the Milky Way Galaxy

a star in the Andromeda Galaxy

a planet in Earth's Solar System

a planet in another star system within the Milky Way Galaxy

An implanted pacemaker supplies the heart with 72 pulses per minute, each pulse providing 6.0 v for 0.65 ms. the resistance of the heart muscle between the pacemaker’s electrodes is 550 ω. find (a) the current that flows during a pulse, (b) the energy delivered in one pulse, and (c) the average power supplied by the pacemaker.

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?

Abar magnet cut in half will form a total ofpoles. a)fourb)eightc)two