A spherical object has an outside diameter of 60.0cm . Its outer shell is composed of aluminum and is 2.80cm thick. The remainder is uniform plastic with a density of 720kg/m3 .

A) Determine the object's average density.

B) Will this object float by itself in fresh water?

An object with a density of 761.0 kg/m³ and a mass of 1399.0 kg is thrown into the ocean. Find the volume that sticks out of the water. (use ?_seawater = 1024 kg/m³)

Describe how at least one of the laws of thermodynamics relates to your room, or the heating or cooling of your room and Comment on three ways to improve the efficiency of your room.

True or Flase, preferably explain the reasoning behind the answer

a)The electric field inside the solid metal sphere is never zero

b)If the solid sphere is an insulator (instead of metal) with net charge Q, the charges are wherever they were placed, and cannot move around.

c) If the solid sphere is an insulator (instead of metal) with net charge Q, the electric field for r >> R would be the same as that of a conductor with the same shape and charge.

d)The net charge on the inside of the solid metal sphere is neutral.

e)The electric field for the metal sphere at r << R will be the same as the field of a point charge, Q, at the origin

f)The electric field near the metal surface on the outside is parallel to the surface.

List the 8 different types of simple machines. The 8th one is harder and less obvious.

Six similar boxes (A–F) are initially sliding in the positive direction along a frictionless horizontal surface at a speed of 10 m/s. Then a net horizontal force, also in the positive direction, is applied to each box for a period of 10 seconds. The masses of the boxes and the net horizontal force for each case are given below.

Rank the boxes in order of increasing FINAL momentum. That is, put first the box with the smallest final momentum, and put last the box with the largest final momentum.

If B is smallest, then A, C, D, and finally E is largest, enter BACDE.
Note: if final momenta are equal, then enter those cases in the order listed.

A) F = 30 N. . . . . . M = 15 kg
B) F = 80 N. . . . . . M = 10 kg
C) F = 70 N. . . . . . M = 15 kg
D) F = 75 N. . . . . . M = 15 kg
E) F = 95 N. . . . . . M = 25 kg
F) F = 110 N. . . . . . M = 10 kg

explain step by step please

1) A projectile returns to its original height after 4.08 seconds, during which time it travels 76.2 meters horizontally. If air resistance can be neglected, what was the projectile's initial speed?

(Use g = 9.80 m/s2)

When we receive an X-ray at the dentist office why do they place a lead apron on our chest? Why is it lead? What type of radiation?

A parallel plate capacitor with plate area 100.0cm² and air-gap separation .500mm is connected to a 12.0 V battery, and fully charged. The batter is then disconnected.

A.) The plates are now pulled to a separation of 1.00mm. What is the magnitude of the charge on each capacitor plate and the magnitude of the E-field between the plates now? ( ?₀ = 8.85 x 10^-12 C²/Nm²)

B.) What is the potential difference across the plates now?

C.) How much work was required to pull the plates to their new separation?

D.) If a proton was released from the + plate and hit the - plate, what speed would it have?

Thanks :D

A 20 g ball of clay traveling east at 3.0 m/s collides with a 30 g ball of clay traveling north at 2.0 m/s. What is the magnitude and direction of initial momentum for each ball before collision? a. What is the momentum of 50 g blob of clay in x? What is the speed in that same direction? b. What is the momentum of 50 g blob of clay in y? What is the speed in that same direction? c. What is the resultant speed of the blob? d. What is direction of the blob?

A placekicker must kick a football from a point 36.0 m (about 40 yards) from the goal. Half the crowd hopes the ball will clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 23.4 m/s at an angle of 48.0° to the horizontal.

(a) By how much does the ball clear or fall short of clearing the crossbar? (Enter a negative answer if it falls short.)
m
(b) Does the ball approach the crossbar while still rising or while falling?

rising or falling

When a small object approaches a much more massive object, the smaller object can be tidally disrupted. The distance of the closest approach before being tidally disrupted is the Roche limit (recall lecture on rings of plan- ets). If the small object is a star and the large object is a supermassive black hole, the Roche limit is given by

rR= 2.4 * RS * (pBH/p*)^(1/3)

where RS is the Schwarzschild radius, ρ̄BH is the average density of the black hole and ρ̄∗ is the average density of the star.

1. a) Setting the average density of the supermassive black hole equal to its mass divided by the volume contained within the Schwarzschild radius, derive an expression for the mass of a black hole as a function of ρ̄∗ that would have rR = RS.

2. b) If the Sun were to fall into a supermassive black hole, what maximum mass could the black hole have if the Sun would be tidally disrupted before crossing the event horizon (or RS). Compare your answer with typical supermassive black holes in the galactic nuclei.

3. c) If the mass of the supermassive black hole exceeded the mass found above, what would be the implication in terms of the energy release of the infalling star? Could infalling stars effectively power AGNs in this case?

1）On a certain dry sunny day, a swimming pool's temperature would rise by 1.40°C if not for evaporation. What fraction of the water must evaporate to carry away precisely enough heat to keep the temperature constant?

2）A piece of iron block moves across a rough horizontal surface before coming to rest. The mass of the block is 3.3 kg, and its initial speed is 3.2 m/s. How much does the block's temperature increase, if it absorbs 74% of its initial kinetic energy as internal energy? The specific heat of iron is 452 J/(kg · °C).

°C

A load of bricks of mass M = 185 kg is attached to a crane by a cable of negligible mass and length L = 3.19 m. Initially, when the cable hangs vertically downward, the bricks are a horizontal distance D = 1.39 m from the wall where the bricks are to be placed. What is the magnitude of the horizontal force that must be applied to the load of bricks (without moving the crane) so that the bricks will rest directly above the wall?

PLEASE, I NEED CORRECT ANSWERS TO ALL THE QUESTION. THEY ARE MULTIPLE CHOICE QUESTIONS. THANK YOU