Physics, 22.04.2020 02:56 chambless1828
In a rocket-propulsion problem the mass is variable. Another such problem is a raindrop falling through a cloud of small water droplets. Some of these small droplets adhere to the raindrop, thereby increasing its mass as it falls. The force on the raindrop is
Fext=dp/dt=m dv/dt+v dm/dt
Suppose the mass of the raindrop depends on the distance x that it has fallen. Then m = kx, where k is a constant, and dm/dt=kv
dm/dt=kv This gives, since Fext=mg
Fext=mg,
mg=m dv/dt+v(kv)
Or, dividing by k,
xg=x dv/dt+v2
This is a differential equation that has a solution of the form v = at, where a is the acceleration and is constant. Take the initial velocity of the raindrop to be zero.
(a) Using the proposed solution for v find the acceleration a.
(b) Find the distance the raindrop has fallen in t = 3.00 s.
(c) Given that k = 2.00 g/m, find the mass of the raindrop at t = 3.00 s.
Answers: 3
Physics, 22.06.2019 04:30
In a voltaic cell, electrons flow from the (positive/negative) to the (positive/negative) terminal.
Answers: 1
Physics, 22.06.2019 08:00
Why is it important always to use horizontal bars in unit fractions when performing unit conversions?
Answers: 3
Physics, 22.06.2019 14:10
What is the weight of a 8-kg substance in n, kn, kg·m/s2, kgf, lbm·ft/s2, and lbf?
Answers: 2
Physics, 22.06.2019 14:40
Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?
Answers: 3
In a rocket-propulsion problem the mass is variable. Another such problem is a raindrop falling thro...
Mathematics, 07.10.2019 13:30
Mathematics, 07.10.2019 13:30
Health, 07.10.2019 13:30
Mathematics, 07.10.2019 13:30
Mathematics, 07.10.2019 13:30
English, 07.10.2019 13:30
Computers and Technology, 07.10.2019 13:30