Aforce platform is a tool used to analyze the performance of athletes measuring the vertical force that the athlete exerts on the ground as a function of time. starting from rest, a 67.0-kg athlete jumps down onto the platform from a height of 0.720 m. while she is in contact with the platform during the time interval 0 < t < 0.800 s, the force she exerts on it is described by the function
f = 9 200t − 11 500t2
where f is in newtons and t is in seconds.
(a) what impulse did the athlete receive from the platform?
n · s up

(b) with what speed did she reach the platform?
m/s

(c) with what speed did she leave it?

(d) to what height did she jump upon leaving the platform?

answer:

a

explanation:

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:

uranium fissions/breaks up giving out energy and neutrons