Answer:
. Doppler ultrasound is based on absorption of sound, and other
ultrasound technology is based on reflection.D.
Explanation:
maximum speed of cheetah is

speed of gazelle is given as

Now the relative speed of Cheetah with respect to Gazelle


now the relative distance between Cheetah and Gazelle is given initially as "d"
now the time taken by Cheetah to catch the Gazelle is given as

so by rearranging the terms we can say


so above is the relation between all given variable
If it is stationary, its not moving. there is no movement
Answer:
3.2N
Explanation:
Given parameters:
Mass of block = 1.5kg
Coefficient of kinetic friction = 0.6
Force of pull on block = 12N
Unknown:
Net force on the block = ?
Solution:
Frictional force is a force that opposes motion:
Net force = Force of pull - Frictional force
Frictional force = umg
u is coefficient of kinetic friction
m is the mass
g is the acceleration due to gravity
Frictional force = 0.6 x 1.5 x 9.8 = 8.8N
Net force = 12N - 8.8N = 3.2N