Question
15 and 16
47 e) None of the abos 15. What is the velocity of the block onve the spring is no longer pushing the blodk (a) 3.2 (b) 2.83 (c) 2.00m (d) 1.58 (e) None of the above (d)-16 e N of the above 1 .A 604 bore tb bleek elessed from rest 80.m meray aher it has fallen a distance 1800 3500 1200 16. How far will the block slide from the equi- position of the spring before it librium stops? (a) 214cm (b) 163cm 120 e None of the above For the following three questions con. 7 along a hocisontal track the spring lder: A spring pushes a mass of m (c) 86.4cm (d) 48.0cm has spring constant of 350 , and niealily compressed a distance of z e There is a coeficieut of kinetic fric- tion of + 0.85 between the block and (e) None of the above
Explanation / Answer
15)
Apply conservation of energy
1/2 mv^2 = 1/2 k x^2
v = sqrt kx^2/ m
= sqrt ( 350) (0.15)^2/0.75
= 3.24 m/s
(16)
1/2 kx^2 = 1/2 mv^2 - uk mg d
1/2 mv^2 - 1/2 kx^2= uk mgd
1/2 * (0.75) ( 3.24)^2 - 1/2 ( 350) (0.15)^2 = 0.85( 0.75) (9.8) d
d= 144 cm
option ( e) is correct answer