Two blocks on a frictionless horizontal surface are on a collision course.One block with mass 0.25 kg moves at 1 m/s to the right collides with a 0.5 kg mass at rest and the two masses stick together. What is the final speed of the blocks after the collision?

          a) -0.33 m/s

          b) +0.33 m/s

          c) 3.27 m/s

          d) 0.67 m/s

          e) 0.25 m/s

QUESTION 2 The Doppler Effect may be used to determine the relative velocity of objects, such as cars on the highway, or stars in the galaxy. When the OBSERVED frequency appears to increase, relative to the source, this means ... ...

the source is moving AWAY FROM the observer.

... the source is moving at the same speed as the observer.

... the source is moving TOWARDS the observer.

... the source and the observer are motionless.

A block is placed on a frictionless ramp at a height of 13.5 m above the ground. Starting from rest, the block slides down the ramp. At the bottom of the ramp, the block slides onto a frictionless horizontal track without slowing down. At the end of the horizontal track, the block slides smoothly onto a second frictionless ramp. How far along the second ramp does the block travel before coming to a momentary stop, as measured along the incline of the ramp?

An electric heater is really just a resistor with a voltage across it. If you want to have 682 W of heat with a voltage V = 112 volts, what resistance (Ω) should the heater coil have?

The fact that BE/A is greatest for A near 60 implies that the range of the nuclear force is about the diameter of such nuclides.

(a) Calculate the diameter of an A = 60 nucleus.
________ fm
(b) Calculate BE/A for ⁵⁶Fe and ¹⁰²Ru. The first is one of the most tightly bound nuclides, while the second is larger and less tightly bound.
⁵⁶Fe
________ MeV
¹⁰²Ru
________ MeV

These are the answered multiple choice questions about the forces in the Student and Backpack problem. Make a clear diagram which properly identifies all of the forces acting on the student (you will also need a similar, separate, diagram for the backpack), and then making the proper arguments leading to the correct answer.

(a) Which is stronger force, the force on the student by the backpack or the force on the backpack by the student?

The two forces are equally strong by Newton's First Law.

(b) Which is the stronger force, the force on the backpack by the student or the weight of the backpack?

The two forces are equally strong by Newton's Third Law.

(c) Which is the stronger force, the force on the student by the backpack or the weight of the backpack?

The force on the student by the backpack is stronger.The two forces are equally strong by a combination of Newton's First Law and Newton's Third Law.

(d) What kind of force is the force on the student by the backpack?

An electromagnetic force.

(e) Which is the stronger force, the contact force on the student by the ground or the weight of the student?

The force on the student by the ground is stronger.

Elastic collisions are said to conserve the total kinetic energy, while inelastic collisions result in some loss of energy. Provide and describe a real-life example of each type. Indicate where you think the lost energy went to for your inelastic example.

Problem #5 : a) Two positive charges, Qa and Qb are placed on opposite sides of a grounded sphere of radius R at distances of 3R and 6R, respectively, from the sphere center. Show that Qb is repelled from the sphere if Qb < QA * (72275/87723)

b) A infinite wire with line charge density λ is placed a distance d above a grounded conducting plane. Assume that the wire is parallel to the x-axis and is located at in the y=0 plane. Find i) the potential above the conducting plane and ii) the charge density on the conducting plane.

Calculate the average binding energy per nucleon of each of the following isotopes.
(a)
52 Cr
24

______ MeV/nucleon

(b)
235 U
92

______ MeV/nucleon

A (field) hockey player is running north at a speed of 8 m⋅s−1. A ball is coming directly towards her from the north at a speed of 18 m⋅s−1. She swings her stick forward, directly north, at a speed of 6 m⋅s−1 measured in her own frame of reference. What is the speed of the ball with respect to the hockey stick?

Relative to the hockey stick, the ball is travelling at ____ m⋅s−1.

Jane's brother Andrew leaves home for school at 8:00 am. He walks at 3.3 kph. At 8:20 am Jane discovers that Andrew has left his homework at home. She decides to follow him on her bicycle and give him his homework, but she wants to be back home in time for an online test at 9 am. What is the minimum constant speed at which she needs to ride? (Hint: At what time of day will they meet?)

Jane must ride at least ______ kph.

A wheel 2.25 m in diameter lies in a vertical plane and rotates about its central axis with a constant angular acceleration of 4.30 rad/s². The wheel starts at rest at t = 0, and the radius vector of a certain point P on the rim makes an angle of 57.3

1. Consider a charge of -1 nC at (-1,0) m, and a charge of +1 nC at (1,0). Calculate the electric potential everywhere in the plane.

2. For the same geometry as in the first problem, calculate the electric field everywhere, using -?V =E. In 2 dimensions, ?V= (?subxV, ?subyV) = ?subxV x^ + ?suby Vy^

Starting from the statement that decay rate is proportional to the number of nuclei in a sample, derive the exponential equation that relates the number of nuclei in a sample to the initial number and the elapsed time. Define all variables used. [3 marks] c) A 1 megaton nuclear bomb produces 0.45 kg of an isotope of 90Sr and the fallout spreads uniformly over an area of 110 km2 . 90Sr decays with a half-life of 29 years. Determine the ground area that holds an amount of radioactivity equal to 9.2 x104 Bq. Define variables used.

ESPECIALLY NEED ANS TO C THANKS

Two masses are connected by a light string, which passes over a frictionless pulley as shown in fig .3 on a the chalkboard. The inclined plane is rough. When m1=10kg , m2 = 3.0 kg and theta = 60degrees, the 10 kg mass moves down the inclined plane and accelerates down the nclined pane at a rate of 2.0m/s^2. Find a) the tension in the string. b)the coefficient of kinetic friction between the 10 kg mass and the inclined plane.

(6) Moons of Mars.
In 1727, Jonathan Swift wrote Gulliver's Travels in which he described two moons orbiting Mars. About 150 years later, the American astronomer Asaph Hall used a large telescope to discover two moons of Mars and they were named Phobos ("fear") and Diemos ("terror"). Their motions were surprisingly close to Jonathan Swift's description. The orbital period of Phobos is 8 hours and that of Diemos about 30 hours.

(2 pts.) (a) Using the information given above and one of Kepler's laws (which one?), explain which moon, Phobos or Diemos, is farther from Mars.

(2 pts.) (b) Describe the motions of Phobos and Diemos as seen by an inhabitant of Mars at, say, 40° north martian latitude.

(Note: Phobos and Diemos both orbit Mars close to Mars' equatorial plane and in the same (counterclockwise) direction that Mars spins. Mars' spin period is close to 24 hours. Drawing diagrams would probably help).

PLEASE EXPLAIN YOUR ANSWERS CLEARLY