scalar multiplication, now, add them up
3.89 rounded to the nearest tenth is 3.9
You go to the tenths place which is 8, and then go to the number next to it. 9 is greater than 5, so you have to round up.
You regroup and get 3.9
3.9
Phillip spent $8.14 in total. Here is how:
2.5 lbs (Monday) + 1.2 lbs (Tuesday) = 3.7 lbs
3.7 lbs • $2.20/per lbs = $8.14
Answer:
1
Step-by-step explanation:
Answer:
the angle is changing at a rate of 0.0375 rad/s when the time is t=8 seconds
Step-by-step explanation:
since the line D that starts from the spectator and follows the plane has the following equation
D² = x² + H² , where H= altitude of the plane , x= horizontal distance
then for x=v*t , where v=speed of the plane and t=time since the plane has passed overhead , we have for the elevation angle
tan θ = x/y = v*t /H
θ = tan⁻¹ ( v*t /H)
the rate of change in the angle of the spectator's sight θ with the time is
dθ/dt = 1/1+(v*t /H)² * (v/H) = (v/H)/[1+ (v/H)²*t²]
for t=8 seconds
dθ/dt = (875 ft/s/21000 ft)/[1+ (875 ft/s/21000 ft)²*(8 s)²] = 0.0375 rad/s
therefore the angle is changing at a rate of 0.0375 rad/s when the time is t=8 seconds
