Answer:
The maximum velocity the mass can have if the string is not to break = 29.05 m/s
Explanation:
The force balance in the mass:
The tension in the string must always be equal to the force keeping the mass in horizontal circular motion.
The force keeping the mass in circular motion is given by
F = mv²/r
m = mass of body = 0.4 kg
v = speed of the body in circular motion
r = radius of the circular motion = 0.75 m
Maximum tension the string can withstand will correspond to the maximum velocity of the body in horizontal circular motion
T = F = mv²/r
450 = (0.4)(v²)/(0.75)
v² = 450×0.75/0.4 = 843.75
v = 29.05 m/s
Answer:
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Answer:
The frequency heard by the motorist is 4313.2 Hz.
Explanation:
let f1 be the frequency emited by the police car and f2 be the frequency heard by the motorist, let v1 be the speed of the police car and v2 be the speed of the motorist and v = 343 m/s be the speed of sound.
because the police car is moving towards the motorist at a higher speed, then the motorist will hear a increasing frequency and according to Dopper effect, that frequency is given by:
f1 = [(v + v2/(v - v1))]×(f2)
= [( 343 + 30)/(343 - 36)]×(3550)
= 4313.2 Hz
Therefore, the frequency heard by the motorist is 4313.2 Hz.
Follow stop drop and roll if the fire is in the room
Other wise exit immediately and find the nearest fire point. Then when you are out phone the fire services.
I hope this helps :)
Answer:
a --> true, b --> false, c --> true, d -->false
Explanation:
a) since it stays floating the gravity force and the upqards push is the same
b) if it's balanced the rocket won't move from the ground, the force of the rocket, has to exceed the force of gravity
c) since it's going in a diretion the force of gravity is exceeding the force pushing it up
d) since that are speeding up at a rate, meaning growing, the force is unbalanced.
