a projectile is launched straight up at 141 m/s . How fast is it moving at the top of its trajectory? suppose it is launched upw
1 answer:
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1) Velocity: 9.9 m/s and 14 m/s
The motion of the diver is a free-fall motion, so it is a uniform accelerated motion. Choosing downward as positive direction, the final velocity can be found by using the following suvat equation:
where
v is the final velocity
u = 0 is the initial velocity (the diver starts from rest)
is the acceleration of gravity
s is the displacement
For the diver jumping from 5 m, s = 5 m, so
For the diver jumping from 10 m, s = 10 m, so
2) Time: 1.01 s and 1.43 s
The time of flight of each diver can be found by using the other suvat equation
And since u = 0, it can be reduced to
For the diver jumping from 5 m, s = 5 m, so we find
For the diver jumping from 10 m, s = 10 m, so we find
The wavelength of the note is 
. Since the speed of the wave is the speed of sound, 
, the frequency of the note is
Then, we know that the frequency of a vibrating string is related to the tension T of the string and its length L by
where
is the linear mass density of our string.
Using the value of the tension, T=160 N, and the frequency we just found, we can calculate the length of the string, L:
Then, we know that the frequency of a vibrating string is related to the tension T of the string and its length L by
where
Using the value of the tension, T=160 N, and the frequency we just found, we can calculate the length of the string, L:
Answer:
B. The truck and mosquito exert the same size force on each other.
Explanation:
Newton's third law (law of action-reaction) states that
"When an object A exerts a force (action) on an object B, then object B exerts an equal and opposite force (reaction) on object A"
In this case, we can call
object A = the truck
object B = the mosquito
Thereforce according to Newton's third law, the force exerted by the truck on the mosquito is equal in magnitude to the force exerted by the mosquito on the truck (and in opposite direction).
The reason for which the mosquito will experience much more damage is the fact that the mosquito's mass is much smaller than the truck's mass, and since the acceleration is inversely proportional to the mass:
the mosquito will experience a much larger deceleration than the truck, therefore much more damage.