4) A hockey puck with a mass of 0.3 kg is sliding along ice considered to be frictionless. The pucks velocity is 20 m/s. The puck now crosses over onto a floor that has a coefficient of kinetic friction equal to 0.35. How far will the puck travel across the floor before it stops? a)3m b)87m c)48m d)92m e)58m 5) A spring with a spring constant of k = 50 me has a natural length of 0.45m. It is attached to the top of an incline that makes a 30 degree angle with the horizontal. The incline is 2.4 m long. A mass of 2 kg is attached to the spring, causing it to be stretched down the incline. Har far down the incline does the end of the spring rest? a) 0.2 m b) 0.45 m c) 0.65 m d) 0.835 m e) 1.2 m 6) A 20 N force is pushing two blocks horizontally along a frictionless floor As shown below. What is the force that the 8 kg mass exerts on the 2 kg mass? a) 4 N b) 8 N c)16N d) 20 N e) 24 N 7) A mass M, is released from rest on an incline that makes a 42 degree angle with the horizontal . In 3 seconds the mass is observed to have gone a distance of 3m. What is the coefficient of kinetic friction between the mass and the surface of the incline? a) 0.3 b) 0.7 c)0.6 d) 0.5 e) 0.3