Answer:
the speed of the satellite is 12,880.53 km/h
Explanation:
Given;
radius of the circular orbit, r = 24,600 km
time taken to revolve around Earth, t = 12 hours
The circumference of the satellite is calculated as;
L = 2πr
L = 2π x 24,600 km
L = 49,200π km
L = 154,566.36 km
The speed of the satellite;
v = L/t
v = 154,566.36 / 12
v = 12,880.53 km/h
Therefore, the speed of the satellite is 12,880.53 km/h
Answer:
Height as seen by the professor = 38.2 m
Explanation:
Angle of throw = θ = 69°
Velocity of throw = v
X component of velocity = v₁ = v cos 69 = 0.3584 v m/s
Vertical component of the velocity = v₂ = v sin 69 = 0.9336 v m/s
v₂ / v₁ = tan 69 = 2.605
v₂ = 2.605 v₁.
Professor sees as if the x component of velocity =0
v (as seen by professor) + v' = 0
=> v as seen by professor = -v' = -10.5 m/s
This shows that y component of the ball's velocity is 2.605 times its x component of velocity.
with respect to the professor, there is only y component of velocity.
v₂' =v₂ = 2.605 ( -10.5) = 27.4 m/s.
Height as seen by the professor = (27.4)² / 2(9.8) = 38.2 m
Complete Question
Martin is conducting an experiment. His first test gives him a yield of 5.2 grams. His second test gives him a yield of 1.3 grams. His third test gives him a yield of 8.5 grams. On average, his yield is 5.0 grams, which is close to the known yield of 5.1 grams of substance. Which of the following are true?
A His results are accurate but not precise.
B His results are neither accurate nor precise.
C His results are both accurate and precise
D His results are precise but not accurate.
Answer:
Correct option is A
Explanation:
From the question we are told that
The yield of the first test 
The yield of the second is 
The third yield is 
The average yield 
The know yield is 
From the data given we see that

Since his average yield is closer to the known yield then the answer is accurate
But since the yield for each test are not repeated the answer is not precise
So the answer is accurate but not precise
Answer:
45C in a minute is
45/60 C in a second
.75 C in a second is 3/4 of an ampere.
Explanation:
The only vertical forces are weight and normal force, and they balance since the surface is horizontal. The horizontal forces are the applied force (uppercase F) in the direction the block slides and the frictional force (lowercase f) in the opposite direction.
Apply Newton's 2nd Law in the horizontal direction:
ΣF = ma
F - f = ma
where f = µmg
F - µmg = ma
F = m(a +µg)
F = (20 kg)(1.4 m/s² + 0.28(9.8 m/s²)
F = 83 N