The amount of energy needed to increase the temperature of a substance by
![\Delta T](https://tex.z-dn.net/?f=%5CDelta%20T)
is given by:
![Q=m C_s \Delta T](https://tex.z-dn.net/?f=Q%3Dm%20C_s%20%5CDelta%20T)
where
m is the mass of the substance
Cs is the specific heat capacity of the substance
![\Delta T](https://tex.z-dn.net/?f=%5CDelta%20T)
is the increase in temperature
In our problem, m=50.0 g,
![C_s = 4.18 J/g ^{\circ}C](https://tex.z-dn.net/?f=C_s%20%3D%204.18%20J%2Fg%20%5E%7B%5Ccirc%7DC)
(specific heat capacity of water) and
![\Delta T=15.0 ^{\circ}C](https://tex.z-dn.net/?f=%5CDelta%20T%3D15.0%20%5E%7B%5Ccirc%7DC)
, therefore the amount of energy needed is
Answer:
The smallest angular velocity is 4.42 rad/s and the largest angular velocity is 13.15 rad/s for the toast to hit and then topple to be butter-side down
Explanation:
62 cm = 0.62 m
Knowing that the vertical distance traveled is s = 0.62 m and gravitational acceleration is g = 9.81 m/s2, we can calculate the time of falling
![s = gt^2/2](https://tex.z-dn.net/?f=s%20%3D%20gt%5E2%2F2)
![0.62 = 9.81t^2/2](https://tex.z-dn.net/?f=0.62%20%3D%209.81t%5E2%2F2)
![t^2 = 2*0.62/9.81 = 0.13](https://tex.z-dn.net/?f=t%5E2%20%3D%202%2A0.62%2F9.81%20%3D%200.13)
![t = \sqrt{0.13} = 0.36 s](https://tex.z-dn.net/?f=t%20%3D%20%5Csqrt%7B0.13%7D%20%3D%200.36%20s)
If there's only 0.36s to rotate, and for the toast to hit and then topple to be butter-side down, then the angle of rotation must be between 90 and 270 degrees (Suppose that it starts with butter up and it rotates less than 1 revolution, or 360 degrees):
In other words (and units):
rad
As
:
rad/s
rad/s
rad/s
So the smallest angular velocity is 4.42 rad/s and the largest angular velocity is 13.15 rad/s for the toast to hit and then topple to be butter-side down
Answer:
(a) 34.4°
(b) 49.4 N
Explanation:
(a) From the diagram,
Amgle between the x axis can be calculated as,
cosΘ = adjacent/hypoteneous
cosΘ = 72.1/87.4
cosΘ = 0.8249
Θ = cos⁻¹(0.8249)
Θ = 34.4°.
Hence the angle between the x axis is 34.4°
(b) To find the component along the y axis we make use of pythagoras theorem.
a² = b²+c²................... Equation 1
Where a = 87.4 N, b = 72.1 N, c = y.
Substitute these values into equation 1
87.4² = 72.1² + y²
y² = 87.4²-72.1²
y² = 2440.35
y = √(2440.35)
y = 49.4 N
Answer:
20
Explanation:
speed= distance / time 60miles/30hour=2miles/hours