Answer with Explanation:
We are given that
Force acts on a pebble= N
Position vector= m
a.We have to find the resulting torque on the pebble about origin.
Torque=
Substitute the values then we get
Torque=N-m
By using
b.
Torque about point (2,0,-3)
N-m
Answer:
B. Steam burns the skin worse than hot water because the latent heat of vaporization is released as well.
Explanation:
It is given that both steam and the boiling water when in contact with the skin cools down from 100 to 34 degrees Celsius.
For any substance of mass m, the heat required to change the temperature by is
(S.I. unit = Joules).
where C, the specific heat capacity is the same and a constant for both the condensed steam and the boiling water.
But, there is a "hidden" energy (heat) released by the steam called latent heat
(given by mL, L = specific latent heat) which allows the phase transition (gas to liquid). While both of them are at the same temperature, their energy (heat) is different, which is why steam causes burns worse than boiling water
Answer:
The angle of elevation of the rocket is increasing at a rate of 48.780º per second.
Explanation:
Geometrically speaking, the distance between the rocket and the observer (), measured in kilometers, can be represented by a right triangle:
(1)
Where:
- Horizontal distance between the rocket and the observer, measured in kilometers.
- Vertical distance between the rocket and the observer, measured in kilometers.
The angle of elevation of the rocket (), measured in sexagesimal degrees, is defined by the following trigonometric relation:
(2)
If we know that , then the expression is:
And the rate of change of this angle is determined by derivatives:
Where:
- Rate of change of the angle of elevation, measured in sexagesimal degrees.
- Vertical speed of the rocket, measured in kilometers per hour.
If we know that and
, then the rate of change of the angle of elevation is:
The angle of elevation of the rocket is increasing at a rate of 48.780º per second.