Question1

A 75 kg human sprinter is able to accelerate from rest to 12 m/s in 3.3 s. all through the same interval, a 33 kg greyhound can accelerate from rest to 20 m/s. calculate

(a) change in kinetic energy and

(b) average power output for each.

Question2

The Hβ line of hydrogen corresponds to a wavelength of 486.133 nm while measured in a lab on Earth. In observations of the star Megrez in Ursa Major, absorption line for Hβ is observed at a wavelength of 486.112 nm. What can we say about radial motion of Megrez along the line of sight from Earth?

Question3

True or False or unable to decide without knowing the shape of the object: If 2 forces of equal magnitude act on an object that is hinged at a pivot, the force acting farther from the pivot point must produce the greater torque about the pivot.