An approximation used to measure building height is 10 feet per building level.
Converting from feet to meters using the equation:
1 ft = 0.3048m
10 ft = 3.048m
Multiplying that by 30 storeys, we get:
3 x 3.048m = 91.44m, which is near the answer of (3) 10^2 m or 100m.
Answer:
The angular acceleration of the wheel is 15.21 rad/s².
Explanation:
Given that,
Time = 5 sec
Final angular velocity = 96.0 rad/s
Angular displacement = 28.0 rev = 175.84 rad
Let
be the angular acceleration
We need to calculate the angular acceleration
Using equation of motion

Put the value in the equation

......(I)
Again using equation of motion

Put the value in the equation

On multiply by 5 in both sides
....(II)
On subtract equation (I) from equation (II)




Hence, The angular acceleration of the wheel is 15.21 rad/s².
Answer:
10 m
Explanation:
5 m/s * 2 s = 10 meters ( see how the ' s ' cancels out?)
The desk is in equilbrium, so Newton's second law gives
∑ <em>F</em> (horizontal) = <em>p</em> - <em>f</em> = 0
∑ <em>F</em> (vertical) = <em>n</em> - <em>mg</em> = 0
==> <em>n</em> = <em>mg</em>
==> <em>p</em> = <em>f</em> = <em>µn</em> = <em>µmg</em> = 0.400 (80.0 kg) <em>g</em> = 313.6 N
The student pushes the desk 3.00 m, so she performs
<em>W</em> = (313.6 N) (3.00 m) = 940.8 Nm ≈ 941 J
of work.
The impulse given to the ball is equal to the change in its momentum:
J = ∆p = (0.50 kg) (5.6 m/s - 0) = 2.8 kg•m/s
This is also equal to the product of the average force and the time interval ∆t :
J = F(ave) ∆t
so that if F(ave) = 200 N, then
∆t = J / F(ave) = (2.8 kg•m/s) / (200 N) = 0.014 s