During the first phase of acceleration we have:
v o = 4 m/s; t = 8 s; v = 13 m/s, a = ?
v = v o + a * t
13 m/s = 4 m / s + a * 8 s
a * 8 s = 9 m/s
a = 9 m/s : 8 s
a = 1.125 m/s²
The final speed:
v = ?; v o = 13 m/s; a = 1.125 m/s² ; t = 16 s
v = v o + a * t
v = 13 m/s + 1.125 m/s² * 16 s
v = 13 m/s + 18 m/s = 31 m/s
<span>Different materials expand and contract at different rates based on temperature. Just like if you leave a plastic bottle full of water in a freezer it will burst, but if you leave it partially full no problem.....Ok?Expansion joints do the same for bridges. There is a gap to allow for temperature related expansions and contractions. Sometimes you drive over bridges and roadways where this movement is constricted and you might notice a bumpy ride. Engineers can predict the variation of structural length based on span lengths and leave the necessary gaps.....btw, NICE QUESTION:)</span>
The answer is B. Unbalanced force
<u>Answers</u>
(a) 6.75 Joules.
(b) 5.27 m/s
(c) 0.75 Joules
<u>Explanation</u>
Kinetic energy is the energy possessed by a body in motion.
(a) its kinetic energy at A?
K.E = 1/2 mv²
= 1/2 × 0.54 × 5²
= 6.75 Joules.
(b) its speed at point B?
K.E = 1/2 mv²
7.5 = 1/2 × 0.54 × V²
V² = 7.5 ÷ 0.27
= 27.77778
V = √27.77778
= 5.27 m/s
(c) the total work done on the particle as it moves from A to B?
Work done = 7.5 - 6.75
= 0.75 Joules
