Answer:
1. 18.25 m/s
2. 0 m/s
Explanation:
1.So the centripetal acceleration of the ball at this lowest point must be, taking gravity into account

The speed at this point would then be


2. Similarly, if T = mg, then the centripetal acceleration must be

As the ball has no centripetal acceleration, its speed must also be 0 as well.
Answer:
The 10-meter long rod of an SR-71 airplane expands 0.02 meters (2 centimeters) when plane flies at 3 times the speed of sound.
Explanation:
From Physics we get that expansion of the rod portion is found by this formula:
(Eq. 1)
Where:
- Expansion of the rod portion, measured in meters.
- Linear coefficient of expansion for titanium, measured in
.
- Initial length of the rod portion, measured in meters.
- Initial temperature of the rod portion, measured in Celsius.
- Final temperature of the rod portion, measured in Celsius.
If we know that
,
,
and
, the expansion experimented by the rod portion is:


The 10-meter long rod of an SR-71 airplane expands 0.02 meters (2 centimeters) when plane flies at 3 times the speed of sound.
Answer:
Yes
Explanation:
Any transparent surface in practical is neither a perfect absorber of electromagnetic waves neither a perfect reflector. Generally all the transparent surfaces reflect some amount of irradiation and the other parts are absorbed and transmitted.
<u>That is given by as relation:</u>

where:
absorptivity which is defined as the ratio of the absorbed radiation to the total irradiation
reflectivity is defined as the ratio of reflected radiation to the total irradiation
transmittivity is defined as the ratio of total transmitted radiation to the total irradiation
-- A tornado follows a path that's a few miles wide, for a few hours.
Then it's all over.
-- A hurricane follows a path that's several hundred miles wide,
for a week or two, before it's over.
Then comes the rain, continuing on the same path, for another week.
Explanation:
Given
mass of the rock is 10 kg
Force requires to hold the rock is equal to its weight
Weight is given by the product of mass and acceleration due to gravity
Weight on the earth surface

Weight on the moon surface

So, the force holding the rock on earth is approximately 6 times the force on the moon.