Select the correct answer. Galileo was the first scientist to do which of the following?
A. estimate the speed of light
B. propose the heliocentric theory
C. discover radioactivity
D. define and measure speed
E. invent the reflecting telescope​

Aferris wheel is a vertical, circular amusement ride with radius 9 m. riders sit on seats that swivel to remain horizontal. the ferris wheel rotates at a constant rate, going around once in 9 s. consider a rider whose mass is 56 kg. at the bottom of the ride, what is the perpendicular component of the rate of change of the rider's momentum? at the bottom of the ride, what is the vector force exerted by the seat on the rider?

Astudent pushes a 60-n block across the floor for a distance of 10 m. how much work was done to move the block

Awave has a wavelength of 7 mm and a frequency of 19 hertz. what is its speed?