Answer:
I think the answer is D,54 joules
Answer:
The conservation of energy should be used to answer this question.
a)
At the position where the spring is unstretched, the elastic potential energy of the spring is zero.

since
and
is equal to zero.

The roots of this quadratic equation can be solved by using discriminant.


We should use the positive root, so
x = 0.292 m.
b)
We should use energy conservation between the point where the spring is momentarily at rest, and the point where the spring is unstretched.

since the kinetic energy at point 2 and the potential energy at point 3 is equal to zero.

Explanation:
In questions with springs, the important thing is to figure out the points where kinetic or potential energy terms would be zero. When the spring is unstretched, the elastic potential energy is zero. And when the spring is at rest, naturally the kinetic energy is equal to zero.
In part b) the cookie slides back to its original position, so the distance traveled, x, is equal to the distance in part a). The frictional force is constant in the system, so it is quite simple to solve part b) after solving part a).
Answer:
The mass of the object on the Moon (and anywhere else) is about 30.61kg. Please see more detail below.
Explanation:
Weight is the gravitational force exerted on the object and is a function of mass and gravitational acceleration:
(weight) = (mass) x (gravitational acceleration)
We are to find the mass, knowing the weight on Earth to be 300N:
(mass) = (weight on Earth) / (gravitational acceleration on Earth) = 300N / 9.8 m/s^2 = 30.61 kg
The mass of the object is 30.61kg.
The mass of the object is independent of gravity. Therefore the answer to the question "What is its mass on the Moon" is 30.61kg.
If the question were what is its weight on the Moon, the answer would be
(weight on Moon) = (mass) x (grav.accel. on Moon) = 30.61kg x 1.62 m/s^2 = 49.59N
which is about 1/6 of the object's weight on the Earth.
Answer:
42.86m
Explanation:
The first thing we should keep in mind is that the watermelon moves with uniform acceleracion equal to gravity (9.81m / s ^ 2)
A body that moves with constant acceleration means that it moves in "a uniformly accelerated motion", which means that if the velocity is plotted with respect to time we will find a line and its slope will be the value of the acceleration, it determines how much it changes the speed with respect to time.
When performing a mathematical demonstration, it is found that the equations that define this movement are as follows.

where
Vf=29m/s= final speed
Vo= initial speed=0m/S
g=gravity=9.81m/s^2
Y= distance traveled(m)
solving

the distance traveled by watermelon is 42.86m
Answer:
The correct answer is option '5': The type of metal from which the plate is made.
Explanation:
According to the principle of photoelectric effect we know that electron's are only emitted from a surface of metal if the frequency of the light is larger than a threshold frequency that depends on the metal and is known as threshold function of the metal. The ejection of the electrons is independent of intensity of the incident light meaning any light of frequency lower than work function will not eject electrons from the metal no matter whatever the intensity of the light, or the surface area or thermal conductivity, time of illumination.