Answer:
W = 311074.5 [J]
Explanation:
In order to solve this problem we must analyze two parts, in the first part by means of Newton's second law we can determine the acceleration of the beam, remembering that the sum of the forces is equal to the product of mass by acceleration.
∑F = m*a
F = forces acting on the beam [N]
m = mass = 425 [kg]
a = acceleration = 1.8 [m/s²]
The forces acting on the beam are the force of the crane up (positive) and the weight of the beam down (negative)
![F_{crane}-(425*9.81)= 425*1.8\\F_{crane}=4713.25 [N]](https://tex.z-dn.net/?f=F_%7Bcrane%7D-%28425%2A9.81%29%3D%20425%2A1.8%5C%5CF_%7Bcrane%7D%3D4713.25%20%5BN%5D)
Now in the second part, we use the definition of work, which is equal to the product of the force applied in the direction of displacement, that is, the product of force by distance.
where:
W = work [J]
F = force = 4713.25 [N]
d = distance = 66 [m]
![W=4713.25*66\\W=311074.5[J]](https://tex.z-dn.net/?f=W%3D4713.25%2A66%5C%5CW%3D311074.5%5BJ%5D)
Answer:
1, 2, 4, 5 are correct
Explanation:
1) This is true because In a neutral atom, the number of positive charges (protons) is equal to the number of negative charges (electrons).
2) This is true because the mass of the atom which is made up of the protons and neutrons, is located in the tiny nucleus.
3) This is not true because the positively charged particles in the nucleus are called protons.
4) This is true because electrons move around the nucleus in diffuse areas known as orbitals.
5) This is true because opposite charges attract each other. And electron is a negative charge.
6) This is not true because the radius of the electron cloud is normally 10,000 times larger than the radius of the nucleus.
The area of the Earth (Ae) that is irradiated by is given by:
Ae = 4πRe^2, where Re = Distance from Sun to Earth
Substituting;
Ae = 4π*(1.5*10^8*1000)^2 = 2.827*10^23 m^2
On the Earth, insolation (We) = Psun/Ae
Therefore,
Psun (Rate at which sun emits energy) = We*Ae = 1.4*2.827*10^23 = 3.958*10^23 kW = 3.958*10^26 W
Answer: 2812500 joules
Explanation:
Mass of car = 1500kg
Velocity of car = 75mph
Kinetic energy = ?
Recall that kinetic energy is the energy possessed by a moving object, and it depends on its mass M and velocity, V
Thus, Kinetic energy = 1/2 x mv^2
= 1/2 x 1000kg x (75mph)^2
= 0.5 x 1000kg x (75mph)^2
= 500 x 5625
= 2812500 joules
Thus, the car travels with a kinetic energy of 2812500 joules
