Answer: A-they change the direction of the forces
Explanation:
Any device which makes our work simpler is known as a machine. A machine may increase the amount of output force which is determined by its mechanical advantage or a machine changes the direction of the force.
In the given situation the input force acts in the downward direction to pull the rope. The output force acts on the flag being pulled upwards at the other end. Thus, the direction of the forces varies. Correct option is A.
Answer:
2.286 km/s²
Explanation:
Since acceleration a = (v - u)/t where u = initial horizontal velocity of ball = 0 m/s (since it starts from rest), v = final horizontal velocity of ball at serve = 73.14 m/s and t = time taken for serve = 32.0 ms = 0.032 s
Substituting the values of the variables into the equation, we have
a = (v - u)/t
a = (73.14 m/s - 0 m/s)/0.032 s
a = 73.14 m/s/0.032 s
a = 2285.625 m/s²
a = 2.285625 km/s²
a ≅ 2.286 km/s²
So, the x - component of the ball's acceleration during the serve is 2.286 km/s²
Answer:
-3802 m/s
Explanation:
The y-component of the final velocity is ...
(6598 m/s)·sin(-20.5°) ≈ -2310.7 m/s
The y-component of the velocity due to acceleration is ...
(5200 m/s²)(0.350 s)sin(55°) ≈ 1490.9 m/s
Then the initial velocity in the y-direction is found from ...
initial velocity + change in velocity = final velocity
initial velocity = (final velocity) - (change in velocity)
= -2310.7 m/s - 1490.9 m/s ≈ -3802 m/s
Answer:
V = sqrt(2M1gh/M2)
Explanation:
Please see the attachment below.
The question is incomplete. Here is the complete question.
The isotope of Plutonium 238Pu is used to make thermoeletric power sources for spacecraft. Suppose that a space probe was launched in 2012 with 3.5 kg of 238Pu.
(a) If the half-life of 238Pu is 87.7 yr, write a function of the form to model the quantity Q(t) of 238Pu left after t years. Round ythe value of k to 3 decimal places. Do not round intermediate calculations.
(b) If 1.7kg of 238Pu is required to power the spacecraft's data transmitter, for low long after launch would scientists be able to receive data? Round to the nearest year. Do not round intermediate calculations.
Answer: (a)
(b) 91 years.
Explanation:
(a) Half-life is time it takes a substance to decrease to half of itself, i.e.:
Q(t) =
k = 0.0079
<u>Knowing k and </u><u>=3.5kg, function is </u><u />
<u />
<u>(</u>b) Using function:
t = 91.41
t ≈ 91 years
<u>Scientists will be able to receive data for approximately 91 years.</u>