Question

The speed of a bobsled is increasing because it has an acceleration of 2.4 m/s2. At a given instant in time, the forces resisting the motion, including kinetic friction and air resistance, total 450 N. The mass of the bobsled and its riders is 235 kg.
(a) What is the magnitude of the force propelling the boblsed forward?
1 N

(b) What is the magnitude of the net force that acts on the bobsled?
2 N

Answer 1

ma=F-F(fr) .
F=ma+F(fr) = 235•2.4 + 450 = 1014 N
(b)
F(net) = ma = 235•2.4 = 524 N

Answer 2

A) Magnitude of the force propelling sled:
F=M*A M= mass of sled and crew A= given acceleration
235Kg*2.4m/s = 564 N
B) Net force is Force +/- all opposing or resisting forces.
450 N works against so it is negative.
564 - 450 N = +114 N = Net force acting upon the sled. :>