Answer:
7revolutions
Explanation:
Given parameters:
Initial revolution = 250rpm
Final revolution = 150rpm
Time = 4.2s
Unknown:
Number of revolutions that occur at this time = ?
Solution:
To solve this problem;
let us find the change in revolution = 250rpm - 150rpm = 100rpm
Convert the time to seconds;
60s makes 1 minute
4.2s will make = 0.07min
So;
The number of revolutions at this time = 100rpm x 0.07min
= 7revolutions
Answer:
bird's speed = 4.58 m/s
Explanation:
given data
mass of bird mb = 300 g
velocity of bird vb = 5.7 m/s
mass of insect mi = 10 g
velocity of insect vi = - 29 m/s
solution
here momentum of system is constant
we apply here conservation of momentum so
mb × v + mi × v = mb × vb + mi × vi ....................1
v ( mb + mi ) = mb × vb + mi × vi
put here value and we get
v ( 300 + 10 ) = { 300 × 5.7 } + { 10 × (-29) }
v =
v = 4.58 m/s
Answer:
34 m/s
Explanation:
m = Mass of glider with person = 680 kg
v = Velocity of glider with person = 34 m/s
= Mass of glider without person = 680-60 kg
= Gliders speed just after the skydiver lets go
= Mass of person = 60 kg
= Velcotiy of person = 34 m/s
As the linear momentum of the system is conserved
The gliders speed just after the skydiver lets go is 34 m/s