Maximum height
= (Usinα)^2/2g
(50*0.5)^2/20
25^2/20
625/20
=31.25metres
horizontal distance = Range= [U^2 * sin2α]/g
[50^2 * sin60]/10
2500 * 0.8660/10
2165/10=216.5metres
Answer: Because new theories can come out that better explain observations and experimental results can replace old theories.
Explanation: Theories more than ten years old are usually out of date. Scientists want to prove that the work of other scientists is wrong. New evidence that supports a change prompts scientists to modify earlier theories.
Answer:
A. The applied force should be the same size as the friction force
Explanation:
Whenever we apply a force to an object it moves if the force applied to that object is unbalanced and there is no force or a lesser force to counter it. According to Newton's Second Law of motion, when an unbalanced force is applied to an object it produces an acceleration in the object in its own direction. So, the two forces acting on this box are the frictional force and the applied force in horizontal direction. In order to move the box at constant speed, the applied force must first, overcome the frictional force, so the object can start its motion. Since, the motion has constant velocity, it means no acceleration. So, the force must be balanced in order to avoid acceleration as a consequence of Newton's Second Law of motion. Therefore, the correction in this case will be:
<u>A. The applied force should be the same size as the friction force</u>
To solve this problem we will apply the concepts related to the conservation of momentum. This can be defined as the product between the mass and the velocity of each object, and by conservation it will be understood that the amount of the initial momentum is equal to the amount of the final momentum. By the law of conservation of momentum,
Here,
= Mass of Basketball
= Mass of Tennis ball
= Initial velocity of Basketball
= Initial Velocity of Tennis ball
= Final velocity of Basketball
= Final velocity of the tennis ball
Replacing,
Solving for the final velocity of the tennis ball
Therefore the velocity of the tennis ball after collision is 11 m/s
