Answer:
![68.0^{\circ}](https://tex.z-dn.net/?f=68.0%5E%7B%5Ccirc%7D)
Explanation:
A projectile's vertical velocity at the top of its flight path must be zero, therefore the speed at the top of the trajectory must be referring to the object's horizontal velocity. Since there are exactly zero horizontal forces acting on the object, its horizontal velocity will remain the exact same throughout the entire launch. Thus, the horizontal component of the initial launch must be 45 meters per second, and we have the following equation using basic trigonometry for a right triangle:
Let
be the unknown angle above the horizontal.
![\cos \theta=\frac{45}{120},\\\theta=\arccos(\frac{45}{120})=67.97568716^{\circ}\approx \boxed{68.0^{\circ}}](https://tex.z-dn.net/?f=%5Ccos%20%5Ctheta%3D%5Cfrac%7B45%7D%7B120%7D%2C%5C%5C%5Ctheta%3D%5Carccos%28%5Cfrac%7B45%7D%7B120%7D%29%3D67.97568716%5E%7B%5Ccirc%7D%5Capprox%20%5Cboxed%7B68.0%5E%7B%5Ccirc%7D%7D)
Answer:
Consider electrons incident on a Young's double slit
If one slit is covered, the electrons will form a maximum, on the screen, as if they were particles incident on the screen
If both slits are open, the pattern formed on the screen will be the same as if a wave were incident on the screen, even tho electrons are slowed to the point that only 1 electron is incident on the screen at one time.
That means that the electron interferes with itself to create the interference pattern on the screen, and there is no way to determine which slit the electron went thru without destroying the interference pattern.
Explanation:
In washing machine, the electrical energy is converted in kinetic energy then the mechanical energy is converted into thermal (heat) energy.
Answer:
15
Explanation:
displacement = initial position - final position
Answer:
Car A has a velocity of 40 km/hr west.
Explanation:
The velocity of an object is a vector quantity. It has both magnitudes as well as direction.
Arrows are used to show direction.
Car A is moving towards west. Car B is moving towards east-south direction. Car C is moving towards South direction. Car E is moving towards North direction.
So, the correct option is (a) i.e. Car A has a velocity of 40 km/hr west.