Answer:
The point on the rim
Explanation:
All the points on the disk travels at the same angular speed 
, since they cover the same angular displacement in the same time. Instead, the tangential speed of a point on the disk is given by
where
is the angular speed
r is the distance of the point from the centre of the disk
As we can see, the tangential speed is directly proportional to the distance from the centre: so the point on the rim, having a larger r than the point halway between the rim and the axis, will have a larger tangential speed, and therefore will travel a greater distance in a given time.
Answer:
dr/dt = -2 cm/s.
Explanation:
The volume of a cone is given by:
(1)
- r is the radius
- h is the height
Let's take the derivative with respect to time in each side of (1).
(2)
We know that:
- dh/dt = 10 cm / s (rate increasing of height)
- dV/dt = 0 (constant volume means no variation with respect of time)
- r = 4 cm
- h = 10 cm
We can calculate how fast is the radius changing using the above information.
Therefore dr/dt will be:
The minus signs means that r is decreasing.
I hope it helps you!
Answer:
9.8 Joules (rounded to 2 significant figures)
Explanation:
Work done (J)= Force(N) x distance changed (m)
- Force= 9.80665 x 0.5kg
- Force= 4.90332 Newtons
- Distance changed= 5-3
- distance changed= 2m/s
--> work done= 4.90332 x 2
work done= 9.8 Joules
Answer:
Commutator reverses the flow of current through an electric motor
Explanation:
