I would say Solar Power Engineer.
According to the cameraman:
Initial velocity: 30 km/hr = 8.33 m/s
Final velocity: -(45 - 20) = -25 km/hr = -6.94 m/s²
a = (-6.94 - 8.33)/2
a = -7.64 m/s²
The direction is opposite to the motion of the car, that is, East.
According to the crew member on ground:
Initial velocity: 20 + 30 = 50 km/hr = 13.89 m/s
Final velocity: -45 km/hr = -12.5 m/s
a = (-12.5 - 13.89) / 2
a = -13.2 m/s²
The direction is the same, East.
The displacement is a vector that is calculated by subtracting the final and initial positions of an object that has made a movement.
We know that initially the object was at the origin and moved to the -8m position.
Suppose that the movement was made on the x-axis. So:
d = [-8 - (0)]x
d = -8x
Regarding the second question.
When the acceleration is constant then the speed changes at a constant rate. Therefore the graph of velocity vs. time will look like a line with a negative slope (if the acceleration is negative) or a line with a positive slope (if the acceleration is positive)
For example. Suppose that the acceleration of gravity is 10
Now suppose you drop an object from a building.
At the initial moment (second 0) the speed is 0 m/s.
After 1 second the speed of the object will be 10 m/s.
After 2 seconds the speed of the object will be 20 m/s.
After 4 seconds the speed will be 40 m/s.
The graph of this example is shown in the attached figure. Note that it is a straight line.
The density of a material is given by:
where
d is the density
m is the mass of the sample
V is its volume
In our problem, the material has a mass of m=2.75 g and a volume of
, so its density is:
So, the correct answer is D).
Answer:
Q = 836.4 Joules.
Explanation:
Given the following data;
Mass = 100 grams
Initial temperature = 25°C
Final temperature = 45°C
We know that the specific heat capacity of water is equal to 4.182 J/g°C.
To find the quantity of heat;
Heat capacity is given by the formula;
Where;
Q represents the heat capacity or quantity of heat.
m represents the mass of an object.
c represents the specific heat capacity of water.
dt represents the change in temperature.
dt = T2 - T1
dt = 45 - 25
dt = 20°C
Substituting the values into the equation, we have;
Q = 836.4 Joules.