Answer:
35 mph
Explanation:
The key of this problem lies in understanding the way that projectile motion works as we are told to neglect the height of the javelin thrower and wind resistance.
When the javelin is thown, its velocity will have two components: a x component and a y component. The only acceleration that will interact with the javelin after it was thown will be the gravety, which has a -y direction. This means that the x component of the velocity will remain constant, and only the y component will be affected, and can be described with the constant acceleration motion properties.
When an object that moves in constant acceleration motion, the time neccesary for it to desaccelerate from a velocity v to 0, will be the same to accelerate the object from 0 to v. And the distance that the object will travel in both desaceleration and acceleration will be exactly the same.
So, when the javelin its thrown, it willgo up until its velocity in the y component reaches 0. Then it will go down, and it will reach reach the ground in the same amount of time it took to go up and, therefore, with the same velocity.
Answer:
7,546 J
Explanation:
recall that Potential energy is given by
P.E = mgΔh
where m = 70kg (given)
g = 9.8 m/s² (acceleration due to gravity)
Δh = change in height
= distance from top of building to top of car
= height of building - height of car
= (5+8) - 2
= 11m
substituting all these into the equation:
P.E = mgΔh
= 70 x 9.8 x 11
= 7,546 J
Answer:
One of the primary advantages of thermal power is that the generation costs are extremely low. No fuel is needed to generate the power, and the minimal energy needed to pump water to the Earth's surface can be taken from the total energy yield.
Explanation:
Answer:
The final kinetic energy of the two-car system is 60,000 J.
Explanation:
Given;
mass of the car, m = 1200 kg
time of motion, t = 8.8 s
final velocity of the car, v = 10 m/s
Apply the principle of conservation of kinetic energy; the initial kinetic energy is equal final kinetic energy.
Therefore, the final kinetic energy of the two-car system is 60,000 J.
The answer is 1.52.
N = C (speed of light) / actual speed
n = index of refraction
