Answer:3m/s
Explanation:
From Newton second law of motion
Change in velocity=(force×time)/mass
Change in velocity=(10×3)/10
Change in velocity=30/10
Change in velocity=3m/s
The efficiency of the bicycle is 20% because 200 out 100 is 2.and ,convert 1000 j out 100 that equal to 10 but,then multiply 2×10 that equal to 20%
Answer:
The maximum height obtained by the object is approximately 31.855 m
Explanation:
The vertical velocity of the object = 25.0 m/s
The height reached by the object, is given by the following formula;
v² = u² - 2 × g × h
Where;
u = The initial velocity of the object = 25.0 m/s
v = The final speed of the object = 0 m/s at maximum height
h = The maximum height obtained by the object
g = The acceleration due to gravity = 9.81 m/s²
Substituting the values, gives;
0² = (25.0 m/s)² - 2 × 9.81 m/s² × h
2 × 9.81 m/s² × h = (25.0 m/s)²
h = (25.0 m/s)²/(2 × 9.81 m/s²) ≈ 31.855 m
The maximum height obtained by the object, h ≈ 31.855 m.
Answer: Physical changes in nature could then be erosion in a mountain, the melting of snow, and a river freezing over from the cold. Since none of these changes affect the chemical composition of the mountain, the snow, or the river, they are physical changes.
Explanation:
Answer:
a. Vf = 39.24 [m/s]
b. Vf = 31.24 [m/s]
c. Vf = 47.24 [m/s].
Explanation:
To solve this problem we can use the following equation of kinematics. We have to keep in mind that the gravitational acceleration acts downwards, therefore when the rock falls towards the abyss it has the same direction of the acceleration and that is why the gravitational acceleration has a positive sign in the equation.
where:
Vf = final velocity [m/s]
Vo = initial velocity = 0 (when the rock is dropped)
g = gravitational acceleration = 9.81 [m/s²]
t = time = 4 [s]
a.
![v_{f}=0+9.81*4\\v_{f}= 39.24 [m/s]](https://tex.z-dn.net/?f=v_%7Bf%7D%3D0%2B9.81%2A4%5C%5Cv_%7Bf%7D%3D%2039.24%20%5Bm%2Fs%5D)
b.
In this particular situation, the acceleration will be taken as negative because the gravity is pointing in the opposite direction of the movement of the rock.
![v_{f}=8-(9.81*4)\\v_{f}=-31.24[m/s]](https://tex.z-dn.net/?f=v_%7Bf%7D%3D8-%289.81%2A4%29%5C%5Cv_%7Bf%7D%3D-31.24%5Bm%2Fs%5D)
The negative sign in the answer tells us that the rock no longer moves up instead it does downwards when 4 seconds have passed.
c.
![v_{f}=8+(9.81*4)\\v_{f}=47.24[m/s]](https://tex.z-dn.net/?f=v_%7Bf%7D%3D8%2B%289.81%2A4%29%5C%5Cv_%7Bf%7D%3D47.24%5Bm%2Fs%5D)
