A physics TA pushes a 20.0 kg equipment cart at a constant velocity for a distance of 28.0 m down the hall. The force she exerts on the cart is directed at an angle 20.0° below the horizontal, and the force of friction opposing the motion of the cart is 48.0 N. Determine the following. (a) the magnitude (in N) of the force exerted on the cart by the TA (b) the work done (in J) by the force the TA exerts on the cart (c) the work done (in J) by the force of friction acting on the cart (d) the work done (in J) by the force of gravity acting on the cart

(a) A 2 kg object is at the base of a 35° incline, initially at rest, and sits on top of a spring (k = 240 N/m) which is parallel to the inline. The spring is compressed 0.40 m from its equilibrium position and then released, propelling the object up the incline. While the object slides it experiences a frictional force of 2.00 N. Diagram this situation below. Remember to include coordinate axes.

(b) Apply conservation of energy to determine the speed of the object at the moment the spring reaches equilibrium. Explain all terms. If any terms equal zero explain why.

(c) Apply conservation of energy to determine how far up the incline the object will reach (above the spring’s equilibrium position). Explain all terms. If any terms equal zero explain why.

(d) Apply conservation of energy to determine how much the spring will compress in stopping the object as it slides back down the incline. Explain all terms. If any terms equal zero explain why.

-How can you determine the distance to a spacecraft from the time it takes its radio signal to reach Earth?

-What do gamma rays, X-rays, light, and radio waves all have in common?

-Which type of reflector telescope would be the easiest to construct, and why?

-Contrast image formation in reflectors and refractors.

-A reflecting telescope has a mirror diameter of 4.0 m. What is the angular resolution of the telescope for red light of wavelength 0.7 μm?

-What is the resolution of a telescope?

-What is true of radio telescopes?

-One advantage of the Hubble Space telescope over ground based ones is that....

1. List the viewing systems for fluoroscopy. What is SNR? What would be an acceptable SNR for a fluoro viewing system? (2 points)

A 25-L sample of an ideal gas with ? = 1.67 is at 250 K and 50 kPa. The gas is compressed adiabatically until its pressure triples, then cooled at constant volume back to 250 K, and finally allowed to expand isothermally to its original state.

a. Sketch this cyclical process in a pV diagram (the sketch should be drawn to scale and labelled).

b. How much work is done on the gas?

c. For each step in the process determine the heat energy.

A star of mass 7 × 10³⁰ kg is located at <6 × 10¹², 3 × 10¹², 0> m. A planet of mass 9 × 10²⁴ kg is located at <5 × 10¹², 5 × 10¹², 0> m and is moving with a velocity of <0.9 × 10⁴, 1.5 × 10⁴, 0> m/s.

a/ During a time interval of 1 × 10⁶ seconds, what is the change in the planet's velocity? (in xyz vector form)

b/ During this time interval of 1 × 10⁶ seconds, what is the change in the planet's position?(in xyz vector form)

Describe how to improve the efficiency of a room related to heat loss.

Heat transfer can occur through conduction, radiation, and convection.

A projectile is fired with an initial speed of 37.1 m/s at an angle of 44.2 ∘ above the horizontal on a long flat firing range. A)Determine the maximum height reached by the projectile.B) Determine the total time in the air. C)Determine the total horizontal distance covered (that is, the range). D)Determine the speed of the projectile 1.70 s after firing.

A wire of length L has a rectangular cross-section with height H and width W. The wire has a hole all the way through it of area a. The wire is made of material with constant resistivity ρ1 . A battery with a known voltage is applied across the ends of the wire. a. Find the electric field inside the material and the current flowing through the wire. b. If the hole is totally filled with a material that has resistivity ρ2 , what will be the electric field everywhere inside the wire, and what current will flow through the wire?

The outside diameter of the playing area of an optical Blu-ray disc is 11.75 cm, and the inside diameter is 4.50 cm. When viewing movies, the disc rotates so that a laser maintains a constant linear speed relative to the disc of 6.70 m/s as it tracks over the playing area.

What is the average angular acceleration of a Blu-ray disc as it plays an 3.5-h set of movies? (Assume the disk is scanned starting at its inner radius moving outward. Express your answer to two significant figures.)

A 27 g ball is fired horizontally with speed v₀ toward a 106 g ball hanging motionless from a 1.13-m-long string. The balls undergo a head-on, perfectly elastic collision, after which the 106 g ball swings out to a maximum angle θ_max=57^°. What was v₀?

(5) Describe the consequences of a 10-km asteroid striking Earth?

Question 7 a. The radius of curvature of a plano-convex lens is measured to be 2 metres, and the focal length in air (n = 1) is measured to be 4 metres. i. What is the power of the lens? [2 marks] ii. What is the refractive index of the lens material? [4 marks] b. A toy Dalek is placed 40 cm in front of a converging lens of focal length f1 = 20 cm; another converging lens 60 cm behind the first has a focal length of f2 = 10 cm. i. Draw a ray trace diagram for this optical system [4 marks] ii. Show where the image produced by the first lens appears on your diagram. Is it a real or virtual image? [3 marks] iii. What is the magnification of the object at the first image? [1 marks] iv. Show where the final image appears on your diagram. Is it a real or virtual image? [3 marks] v. What is the magnification of the first image at the final image? [1 mark] vi. What is the magnification of the object at the final image? [2 marks]

An unmarked police car traveling a constant 80.0 km/h is passed by a speeder traveling 115 km/h . Precisely 1.50 s after the speeder passes, the police officer steps on the accelerator; if the police car's acceleration is 2.50 m/s2 , how much time passes before the police car overtakes the speeder after the speeder passes (assumed moving at constant speed)?