solution:
y = v0t + ½at²
1150 = 79t + ½3.9t²
0 = 3.9t² + 158t - 2300
from quadratic equations and eliminating the negative answer
t = (-158 + v158² -4(3.9)(-2300)) / 2(3.9)
t = 11.37 s to engine cut-off
the velocity at that time is
v = v0 + at
v = 79 + 3.9(11.37)
v = 123.3 m/s
it rises for an additional time
v = gt
t = v/g
t = 123.3 / 9.8
t = 12.59 s
gaining more altitude
y = ½vt
y = 123.3(12.59) /2
y = 776 m
for a peak height of
y = 776 + 1150
Answer:
Explanation:
Total tension must support the weight of the child and provide the necessary centripetal force.
2T = m(g + v²/R)
2(414) = 35.0(9.81 + v²/3.02)
828 = 35.0(9.81 + v²/3.02)
23.65 = 9.81 + v²/3.02
13.847 = v²/3.02
41.81 = v²
v = 6.47 m/s
F = 2(414) = 828 N (ignoring the weight of the chains and seat)
Answer:
final equilibrium temperature of the system is ZERO degree Celcius
Explanation:
Hear heat given by water + iron = heat absorbed by ice
so here first we will calculate the heat given by water + iron
now the heat absorbed by ice so that it will melt and come to the final temperature
now we will have
since it is coming out negative which is not possible so here the ice will not completely melt
so final equilibrium temperature of the system is ZERO degree Celcius
Well first of all, here's something you're going to need:
Power = (energy) / (time) 1 watt = (1 joule) per second
Energy = (power) x (time) 1 joule = (1 watt) x (1 second)
At this point, your progress grinds to a stop, because, technically, the
current alone doesn't tell you the power. In other words, 'Amperes'
alone doesn't give you the 'watts'.
Power (watts) = (amperes) times (volts) .
So you need to either go ask somebody or else <em>assume</em> the <u>voltage</u>
of the outlet that the microwave oven is plugged into. Without it,
the question can't be answered.
I'm going to assume that you live and go to school somewhere in the USA,
Canada, or Mexico. If that's true, then the outlets in your house supply
electrical energy at 120 volts, and everything you plug into them is designed
to run on 120 volts. Now you have enough information to solve the problem.
Power = (15 amperes) x (120 volts) = 1,800 watts
Energy = (power) x (time) =
(1,800 watts) x (20 minutes) x (60 seconds/minute) =
2,160,000 watt-seconds = <em>2,160,000 joules</em>
