Answer:
The initial speed of the ball is 30 m/s.
Explanation:
It can be assumed that the ball is thrown at an angle of 45 degrees to the ground. The ball lands 90 m away. We need to find the initial speed of the ball. We know that the horizontal distance covered by the projectile is called its range. It is given by :
u is the initial speed of the ball.
v = 29.69 m/s
or
v = 30 m/s
So, the initial speed of the ball is 30 m/s. Hence, this is the required solution.
5.47 m
The bullet undergoes a non-elastic collision with the block of wood and momentum is conserved. The initial momentum is 0.029 kg * 510 m/s = 14.79 kg*m/s. The combined mass of the block and bullet is 1.40 kg * 0.029 kg = 1.429 kg. Since momentum is conserved, the velocity of both combined will then be 14.79 kg*m/s / 1.429 kg = 10.34989503 m/s.
With a local gravitational acceleration of 9.8 m/s^2, it will take 10.34989503 m/s / 9.8 m/s^2 = 1.056111738 s for their upward velocity to drop to 0, just prior to descending.
The equation for distance under constant acceleration is
d = 0.5 A T^2
so
d = 0.5 * 9.8 m/s^2 * (1.056111738 s)^2
d = 4.9 m/s^2 * 1.115372003 s^2
d = 5.465322814 m
Rounding to 3 significant figures gives a height of 5.47 meters.
Answer:
An reversal in the magnetic fields of the north and south pole. This would be the most logical option for me...correct me if I'm wrong.
Explanation:
New seafloor is formed when magma is forced upward toward the surface at a mid-ocean.
Answer:
It's B, anything about a circle is Stationary
Answer:
People firstly believe that the planets move in a circular orbit until Newton came up with his hypothesis by inventing calculus so that we could understood and calculated planetary orbits and their accuracy.
Explanation:
- Everyone assumed the planets were perfect circles until Newton came up with an idea. Slowly people would make maps of the orbits that added circles on circles, and they could never really explain about the movement of the planet. They simply say that planets move on circles but they lacked the math to explain or prove it. Then Newton came up with an idea of inventing calculus so that we could understood and calculated planetary orbits and their accuracy.
-
- Firstly people used their observations and say that the orbits looked like circles, then they developed their models and did the math, and proposed their hypothesizes which were wrong, until Newton came along and tried to match a model that used elliptical orbits and invented the math that allowed him to make predictions with it. His model worked for most planets.
-
- However he could not explain about the planet Mercury for instance since it was a very strange orbit. Then after the Einstein's theory of General Relativity he could also explain very deeply about it.
-
- Scientists and Astronomers made hypothesizes that there was another planet orbiting too close to the sun to see with telescopes, called Vulcan, that explained mercury's orbit before Einstein's theory. Then long after we had telescopes which was good enough to see if there was a planet orbiting closer to the sun than mercury.
