A young girl with mass 45.0 kg is sliding on a horizontal, frictionless surface

Question

A young girl with mass 45.0 kg is sliding on a horizontal, frictionless surface with an initial momentum that is due east and that has a magnitude of 94.5 kgm/s. Starting at t=0 , a net force with magnitude
F=(8.10 N/s)t
and direction due west is applied to the girl. (a) At what value of t does the girl have a westward momentum of magnitude 63.0 kgm/s? (b) How much work has been done on the girl by the force in the time interval from t= 0 to the time calculated in part (a)? (c) What is the magnitude of the acceleration of the girl at the time calculated in part (a)?

I would appreciate If you could explain the calculations in detailed manner

Explanation / Answer

a) Impulse = change in momentum = final momentum - initial momentum

4.05t^2= 63-(-94.5)

t=8.82s.

b)work done = change in kinetic energy

=(63^2-94.5^2)/(2*45)

=-55.125 J.

c)At that time,

Force =8.1*8.82 N

=71.44 N

mass = 45 kg

acc. = 71.44/45 m/s^2

=1.58 m/s^2

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.