Answer:
The kinetic energy is 16 joules.
Explanation:
Kinetic energy (E) is given by:
Where:
m: is the mass
v: is the speed
When the kinetic energy is 4 joules, the speed of the object is:
Now, if the speed is increased twice then we have:
![E_{2} = \frac{1}{2}mv_{2}^{2} = \frac{1}{2}m(2v_{1})^{2} = \frac{1}{2}m[4(\frac{8}{m})] = 16 J](https://tex.z-dn.net/?f=%20E_%7B2%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7Dmv_%7B2%7D%5E%7B2%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7Dm%282v_%7B1%7D%29%5E%7B2%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7Dm%5B4%28%5Cfrac%7B8%7D%7Bm%7D%29%5D%20%3D%2016%20J%20)
Therefore, the kinetic energy is 4 times the initial value.
I hope it helps you!
Answer:
18.9 m.
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Final velocity (v) = 70 km/h
Height (h) =?
Next, we shall convert 70 km/h to m/s. This can be obtained as follow:
3.6 km/h = 1 m/s
Therefore,
70 km/h = 70 km/h × 1 m/s / 3.6 km/h
70 km/h = 19.44 m/s
Finally, we shall determine the height. This can be obtained as follow:
Initial velocity (u) = 0 m/s
Final velocity (v) = 19.44 m/s
Acceleration due to gravity (g) = 10 m/s²
Height (h) =?
v² = u² + 2gh
19.44² = 0² + (2 × 10 × h)
377.9136 = 0 + 20h
377.9136 = 20h
Divide both side by 20
h = 377.9136 / 20
h = 18.9 m
Thus, the car will fall from a height of 18.9 m
Answer:
Explanation:
The volume of contaminated water
= cross sectional area x height of water level
3.14 x 9 x 9 x 7.5 ft³
= 1907.55 ft³
mass = density x volume
= 1907.55 x 63.5 lbs
m = 121129.425 lbs
This mass has to be raised to the height of 8 ft before evacuation .
There is a rise of centre of mass of
8 - 7.5/2 ft
h = 4.25 ft
Energy required
= mgh
= 121129.425 x 32 x 4.25
= 16473601.8 unit.
A and c
Because it defines the boundaries of the system
Ok srry bout last time but the answer is A) kelvin: time the reason is because everything else is a SI. Hope this helps and TURTLE
