210 Pb ---> -ie + 210 B:
84 8.3
Answer:
v = 10 m/s
Explanation:
Let's assume the wheel does not slip as it accelerates.
Energy theory is more straightforward than kinematics in my opinion.
Work done on the wheel
W = Fd = 45(12) = 540 J
Some is converted to potential energy
PE = mgh = 4(9.8)12sin30 = 235.2 J
As there is no friction mentioned, the remainder is kinetic energy
KE = 540 - 235.2 = 304.8 J
KE = ½mv² + ½Iω²
ω = v/R
KE = ½mv² + ½I(v/R)² = ½(m + I/R²)v²
v = √(2KE / (m + I/R²))
v = √(2(304.8) / (4 + 0.5/0.5²)) = √101.6
v = 10.07968...
If your speed changes from 10 km/h to 6 km/h then
you have an acceleration.
Whether it's a positive or negative one completely depends
on which direction you decided to call the positive direction,
when you started considering your speed and its changes.
If you decided to call the direction in which you're traveling
the positive direction, then a decrease in your speed is a
negative acceleration.
But you could just as easily have said that you're traveling
in the negative direction. If you did that, then a decrease in
your speed would be a positive acceleration.
It's completely up to you, and how you define things.
Answer:
Explanation:
Given
Required
Determine the speed of the jet
The speed is calculated as:
Substitute 4800 km for Distance and 6hr for Time
<em>Hence, the speed of the commercial jet is 800km/hr</em>
