Answer:
20 m/s
Explanation:
The stored energy is transformed to kinetic energy and since kinetic energy is given by
where m is the mass of arrow in Kg and v is the velocity of the arrow in m/s. From the principle of energy, all the energy is transformed to KE.
KE= Energy stored in bow
Changing mass from 50 g to Kg we divide by 1000 hence m=50/1000=0.05 Kg
Substituting 0.05 Kg for m and 10 J for KE then we have
0.5\times 0.05\times v^{2}=10 J
Making v the subject of the formula then
Therefore, the velocity is equivalent to 20 m/s
Answer:
The work done by gravity is 784 J.
Explanation:
Given:
Mass of the block is, 
Height to which it is raised is, 
Acceleration due to gravity is, 
Now, work done by gravity is equal to the product of force of gravity and the distance moved in the direction of gravity. So,
Force of gravity is given as the product of mass and acceleration due to gravity.
. Now,
Therefore, the work done by gravity is 784 J.
Answer:
maximum height: p(t) = Vo * t - 1/2 * g * t^2
p’(t) = v(t) = 0 = Vo - g*t. So, maximum height occurs when t = Vo / g
p(Vo / g) = Vo^2/g - 1/2 * g * (Vo/g)^2
Vo = 10 m / s. Let’s approximate g = 10 m / s^2
p(Vo / g) = 10^2 / 10 - 1/2 * 10 * (10/10)^2 = 10 - 5 = 5 meters (approximately)
Calculation of time:
v = u + gt
0 = 10√2 + (-10)t
-10√2 = -10t
2 = √2s
<u>Answer:</u>
This figure shows the Second Kepler’s Law of Planetary Motion, <em>The line that joins the planet with the Sun sweeps equal areas in equal times</em>.
According to this statement, the only way in which this is fulfilled is that the planet moves faster when it is <u>near the sun (perihelion)</u> and moves slower when it is <u>far from the Sun (aphelion</u>).
In the image shown, if points W and X are at the same distance to the Sun, this means the instantaneous velocity of the planet in both points is the same.
