Answer:
60km/hr due east
Explanation:
Given parameters:
Displacement = 60km East
Start time = 10am
End time = 11am
Unknown:
Average velocity = ?
Solution:
The average velocity is the displacement divided by the time taken.
For this journey, the time taken is;
11am - 10am = 1hr
So;
Average velocity = 
= 60km/hr due east
(1) First compute the linear speed of the mass. If it completes 1 revolution in 0.5 seconds, then the mass traverses a distance of 2<em>π</em> (1.0 m) ≈ 2<em>π</em> m (the circumference of the circular path), so that its speed is
<em>v</em> = (1/0.5 rev/s) • (2<em>π</em> m/rev) = 4<em>π</em> m/s ≈ 12.57 m/s
Then the centripetal acceleration <em>a</em> is
<em>a</em> = <em>v</em>² / (1.0 m) = 16<em>π</em>² m/s² ≈ 160 m/s²
(where <em>r</em> is the path's radius).
(2) By Newton's second law, the tension in the string is <em>T</em> such that
<em>T</em> = (0.50 kg) <em>a</em> = 8<em>π</em>² N ≈ 79 N
<u>13788 J is required to finish the work.</u>
Explanation:
Given that,
Mass of lawnmower is 20 kg
Force = 30 N
Displacement ( distance moved )= 20m
The force of 30N is applied along the direction of motion and was applied for the whole 20 m.
The formula of work done for one pass is
Substituting the given data into the formula,
W = 459.6 J
Work done for one pass = 459.6J
Now, work done for 30 passes is calculated by multiplying the work done for one pass into 30.
Work is done by the person pushing the mower to finish the work is <u>13788 J</u>.
Sonic boom can also be created from an atomic bomb going off.
1110 atm
Let's start by calculating how many cm deep is 36,000 feet.
36000 ft * 12 in/ft * 2.54 cm/in = 1097280 cm
Now calculate how much a column of water 1 cm square and that tall would mass.
1097280 cm * 1.04 g/cm^3 = 1141171.2 g/cm^2
We now have a number using g/cm^2 as it's unit and we desire a unit of Pascals ( kg/(m*s^2) ).
It's pretty obvious how to convert from g to kg. But going from cm^2 to m is problematical. Additionally, the s^2 value is also a problem since nothing in the value has seconds as an unit. This indicates that a value has been omitted. We need something with a s^2 term and an additional length term. And what pops into mind is gravitational acceleration which is m/s^2. So let's multiply that in after getting that cm^2 term into m^2 and the g term into kg.
1141171.2 g/cm^2 / 1000 g/kg * 100 cm/m * 100 cm/m = 11411712 kg/m^2
11411712 kg/m^2 * 9.8 m/s^2 = 111834777.6 kg/(m*s^2) = 111834777.6 Pascals
Now to convert to atm
111834777.6 Pa / 1.01x10^5 Pa/atm = 1107.2750 atm
Now we gotta add in the 1 atm that the atmosphere actually provides (but if you look closely, you'll realize that it won't affect the final result).
1107.274 atm + 1 atm = 1108.274 atm
And finally, round to 3 significant figures since that's the accuracy of our data, giving 1110 atm.
