Two kids are playing on a newly installed slide, which is 3 m long. john, whose mass is 30 kg, slides down into william (20 kg), who is sitting at the very bottom end, and whom he holds onto when he arrives. laughing, john & william leave the slide horizontally and land in the muddy ground near the foot of the slide. (a) if john starts out 1.8 m above william, and the slide is essentially frictionless, how fast are they going when they leave the slide? (b) to the mud he acquired, john will now experience an average frictional force of 105 n as he slides down. how much slower is he going when he reaches the bottom than when friction was absent?

Explanation:

Given:

(A)

height between John and William,

Using the equation of motion:

where:

v_J = final velocity of John at the end of the slide

u_J = initial velocity of John at the top of the slide = 0

Now putting respective :

Now using the law of conservation of momentum at the bottom of the slide:

Sum of initial momentum of kids before & after collision must be equal.

where: v = velocity with which they move together after collision

is the velocity with which they leave the slide.

(B)

Now we find the force along the slide due to the body weight:

Hence the net force along the slide:

Now the acceleration of John:

Now the new velocity:

Hence the new velocity is slower by

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.