A 50 kg uniform square sign, 2.00 m on a side, is hung from a 3.00 m rod of negligible mass. A cable is attached to the end of the rod and to a point on the wall 4.00 m above the point where the rod is fixed to the wall. What is the tension in the cable?

What is the horizontal component of the force exerted by the wall on the rod?

What is the vertical component of the force exerted by the wall on the rod?

Please answer part A

Three spaceships all broadcast a signal at the same frequency f₀. Spaceship #1 is at rest, spaceship #2 is traveling away from #1 at a speed v, and spaceship #3 is traveling away from #1 in a direction opposite that of #2 and also at a speed v. Determine the following in terms of f₀ when v = 0.40c.

(a) Frequency measured by #1 broadcast from #2

(b) Frequency measured by #1 broadcast from #3

(c) Frequency measured by #2 broadcast from #1

(d) Frequency measured by #2 broadcast from #3

(e) Frequency measured by #3 broadcast from #1

(f) Frequency measured by #3 broadcast from #2

1)A 861 g rubber ball is dropped from height 15.1 m, and it rebounds to height 3.15 m. Assuming there is no air friction, find the magnitude of the impulse, in N-s, exerted by the ground on the ball.

2)Milly (mass 98.7 kg) runs at 2.73 m/s along the positive x-axis and then jumps onto a stationary 278 kg box. Milly and the box slide across the floor for distance 0.357 m, and then they come to a stop. Find the coefficient of kinetic friction between the box and the floor.

3)Two astronauts float in deep space, at rest relative to each other. Including the equipment they carry, the first astronaut has total mass 521 kg and the second astronaut has total mass 615 kg. The first astronaut throws a 656 kg box of tools at 4.66, and the second astronaut catches the box. After the throw and catch: find the speed of one astronaut relative to the other, in m/s.

Please answer with a written response rather than calculations:

-describe conservation of momentum in elastic AND inelastic collisions

-describe the path of the center of mass for two colliding objects

-explain the relationship between conservation of energy in a collision and coefficient of restitution

-explain conversions between kinetic, gravitational potential, and magnetic potential energy

thanks

Consider a box with a lid 2.1 m wide and 0.62 m long. If the inside of the box is evacuated (i.e., its pressure is zero), how much force is required to open the lid?

The development of the internal-combustion engine caused fundamental changes in urban land-use patterns. The transformation from the core-dominated city to the modern suburbanized city took only about 50 years. Given the rapid pace of technological change, it seems likely that some future innovation will cause another transformation of cities. Given your knowledge of science fiction and fact, describe an innovation that would cause fundamental changes in the spatial structure of cities

Suppose you’re eating in yet another restaurant where the dishes are shared at the table and all placed uniformly on a rotating disk-like surface. Model this surface as a thin disk of radius 45.3 cm. Someone else has spun the surface, such that it is initially at an angular speed of 0.4 rev/s. The surface and food has a combined mass of 3.3 kg. The waiter, to show off, throws a new dish of dumplings (mass 0.8 kg) onto the surface at a speed of 0.5 m/s, such that the dish lands on and sticks to the very edge of the surface moving in the same direction as the rotating food. While this is happening, you quickly calculate the final angular speed of the food so that you can predict its location at any time before others have a chance to eat the dumplings. What is this speed, in rad/s?

PLEASE ANSWER ALL

1) Calculate the force of attraction due to gravity, between the Mars and the Sun .

2) Calculate the escape velocity from the planet Venus using the planets known mass and radius.

3)A satellite needs to be 23,000 ( 1609 meters in 1 mile) miles above Earth’s center to be Geo stationary, what speed must it be moving at?

4) What mass must a star have if it is circled by a planet every 0.61 years at a distance of .72 AU ?

5) Calculate the velocity to be in orbit around Venus , at a distance of 100,000,000 meters from the center of the planet.

a. Consider a laser radar emitting a Gaussian beam of diameter 20 cm with a wavelength of 2.1 μm. At distances of 50, 500, 5000, and 50,000 meters, what is the focused beam diameter, and what is the depth of field? Remember the depth of field is twice the Rayleigh range of the waist diameter. Remember that in some cases the solution may be impossible. Also re- member that there may be two solutions, and it makes sense to pick the one with the smaller beam diameter.

b. In view of your answers, comment on the feasibility of using a focusing to select a range with this laser radar.

List the types of noise and their sources. What are the various ways of enhancing Signal-toNoise ratio?

A small block on a frictionless horizontal surface has a mass of 2.95×10⁻² kg . It is attached to a massless cord passing through a hole in the surface. (See the figure below (Figure 1) .) The block is originally revolving at a distance of 0.295 m from the hole with an angular speed of 1.85 rad/s . The cord is then pulled from below, shortening the radius of the circle in which the block revolves to 0.140 m . You may treat the block as a particle.

1.What is the new angular speed in rad/s?

2.Find the change in kinetic energy of the block.

3.How much work was done in pulling the cord?

spaceship travels at a speed of 0.95c to the nearest star, Alpha Centauri, 4.3 light years (ly) away. How long does the trip take from the point of view of the passengers on the ship?

A. 1.4 ly

B. 1.0 ly

C. 4.5 ly

D. 14 ly

E. 0.44 ly

Is it possible for an object to have more than one type of charge at the same time?

What is the smallest number of whole logs (density = 695 kg/m³, radius = 0.073 m, length = 2.73 m) that can be used to build a raft that will carry 6 people, each of whom has a mass of 87.5 kg?