Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and the Yahoo Answers website is now in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Physics please help!!?
1. A person standing at the edge of a seaside cliff kicks a stone over the edge with a speed of vi = 11 m/s. The cliff is h = 44 m above the water's surface, as shown below.
(a) How long does it take for the stone to fall to the water?
___s
(b) With what speed does it strike the water?
___m/s
2.A shell is fired from the ground with an initial speed of 1.76 ✕ 103 m/s at an initial angle of 31° to the horizontal.
(a) Neglecting air resistance, find the shell's horizontal range.
m
(b) Find the amount of time the shell is in motion.
3. A 14,800 N car traveling at 57.0 km/h rounds a curve of radius 2.50 ✕ 102 m.
(a) What is the centripetal acceleration of the car?
m/s2
(b) What is the centripetal force?
N
(c) What is the minimum coefficient of static friction between the tires and the road that will allow the car to round the curve safely?
ANYTHING WILL HELP THANK YOU
1 Answer
- Anonymous4 years agoFavorite Answer
a) Time to drop 44m = sqrt.(2h/g) = sqrt.(88/9.8) = 3 secs.
b) Vertical V component at splashdown = (gt) = (9.8 x 3) = 29.4m/sec.
The horizontal V component was 11m/sec.
Speed at water = sqrt.(29.4^2 + 11^2) = 31.39m/sec.
Initial vertical V component = (sin 31 x 1760m/sec) = 906.47m/sec.
Horizontal component = (cos 31 x 1760) = 1,508.6m/sec.
b) Time in air = 2(v/g) = 2(906.47/9.8) = 185 secs.
a) Range = (185 x 1,508.6) = 279,091 metres.
(57/3.6) = 15.83m/sec.
a) Acceleration = (v^2/r) = (15.83^2/250) = 1m/sec^2.
b) Centripetal force = (ma) = (14,800/g) x 1 = 1 (14,800/9.8) = 1,510.2N.
Normal force from road = 14,800N.
c) µK = (1,510/14,800) = 0.102.
Do I get the credit for your homework?