[amp_mcq option1=”400 watts” option2=”500 watts” option3=”4000 watts” option4=”None of these” correct=”option1″]<\/p>\n
The correct answer is A. 400 watts.<\/p>\n
The power developed by the boy is given by:<\/p>\n
$P = \\frac{W}{t}$<\/p>\n
where $W$ is the work done and $t$ is the time taken.<\/p>\n
The work done in climbing up the rope is given by:<\/p>\n
$W = mgh$<\/p>\n
where $m$ is the mass of the boy, $g$ is the acceleration due to gravity, and $h$ is the height of the rope.<\/p>\n
The height of the rope is given by:<\/p>\n
$h = 8 \\text{ m}$<\/p>\n
The mass of the boy is given by:<\/p>\n
$m = 50 \\text{ kg}$<\/p>\n
The acceleration due to gravity is given by:<\/p>\n
$g = 9.8 \\text{ m\/s}^2$<\/p>\n
Therefore, the work done in climbing up the rope is:<\/p>\n
$W = (50 \\text{ kg})(9.8 \\text{ m\/s}^2)(8 \\text{ m}) = 3920 \\text{ J}$<\/p>\n
The time taken to climb up the rope is given by:<\/p>\n
$t = 10 \\text{ s}$<\/p>\n
Therefore, the average power developed by the boy is:<\/p>\n
$P = \\frac{3920 \\text{ J}}{10 \\text{ s}} = 392 \\text{ W}$<\/p>\n
Since the options are given in multiples of 100, we can round 392 to 400. Therefore, the correct answer is A. 400 watts.<\/p>\n
Option B is incorrect because it is twice the actual power. Option C is incorrect because it is 10 times the actual power. Option D is incorrect because it is not a possible value of power.<\/p>\n","protected":false},"excerpt":{"rendered":"
[amp_mcq option1=”400 watts” option2=”500 watts” option3=”4000 watts” option4=”None of these” correct=”option1″]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[645],"tags":[],"class_list":["post-6685","post","type-post","status-publish","format-standard","hentry","category-applied-mechanics-and-graphic-statics","no-featured-image-padding"],"yoast_head":"\n