The amount of heat needed to raise the temperature of a substance by
is given by
where
m is the mass of the substance
Cs is its specific heat capacity
is the increase in temperature
For oxygen, the specific heat capacity is approximately
The variation of temperature for the sample in our problem is
while the mass is m=150 g, so the amount of heat needed is
Sounds like the shingle/ball is thrown from the roof horizontally, so that the distance it travels <em>x</em> after time <em>t</em> horizontally is
<em>x</em> = (7.2 m/s) <em>t</em>
The object's height <em>y</em> at time <em>t</em> is
<em>y</em> = 9.4 m - 1/2 <em>gt</em>²
where <em>g</em> = 9.80 m/s² is the magnitude of the acceleration due to gravity, and its vertical velocity is
<em>v</em> = -<em>gt</em>
(a) The object hits the ground when <em>y</em> = 0:
0 = 9.4 m - 1/2 <em>gt</em>²
<em>t</em>² = 2 * (9.4 m) / (9.80 m/s²)
<em>t</em> ≈ 1.92 s
at which time the object's vertical velocity is
<em>v</em> = -<em>g</em> (1.92 s) = -18.8 m/s ≈ -19 m/s
(b) See part (a); it takes the object about 1.9 s to reach the ground.
(c) The object travels a horizontal distance of
<em>x</em> = (7.2 m/s) * (1.92 s) ≈ 13.8 m ≈ 14 m
Answer:v=3.28 m/s
Explanation:
Given
mass of rock 
diameter of circle 
radius 
At highest Point
At highest Point N=0 because mass is just balanced by centripetal Force
thus 
Answer:
3 N to the right
Explanation:
There are two forces acting on the car:
- A force of 10 N towards the right
- A force of 7 N towards the left
Therefore, the net force is given by the difference between the two, since they are in opposite directions:
And the direction is to the right, since the force to the right has greater magnitude than the force to the left.
