Other Physics Answers

In a certain region an electric potential V is present. An unknown charge Q is moved around this region between points at potential difference ΔV. A physicist measures the change in the potential energy ΔU as the charge is moved. The table below shows the data of the measurements. The unit for ΔV are MV (mega-Volts), the units for ΔU are kJ (kilo-joules).

ΔV

57.1

29.9

16.7

9.97

8.55

8.32

6.52

6.87

ΔU

362.8

157.6

124.3

55.3

48.8

53.9

37.9

47.3

You want to find the value of the unknown charge Q in mC. Since ΔU = QΔV make the plot 𝑦=𝑚𝑥 where 𝑦=𝛥𝑈 and 𝑥=𝛥𝑉. Use Excel, calculator or whatever you prefer. From the slope of the plot, calculate Q.

1.) The height from the ground to point A is 10m, from ground to point B is 6m, and from ground to point E is 1m. If the ball weights 100 N. What is the change in energy of the ball from point x to point y?

a. 10,000 J

b. 100 J

c. 0 J

d. 1000 J

2.) The height from the ground to point A is 10m, from ground to point B is 6m, and from ground to point E is 1m. If the ball weights 100 N, and its speed doubles as it reaches point C, what is its speed at point C?

a. 0 m/s

b. 8.94 m/s

c. 4.47 m/s

d. 34.64 m/s

A 6-footer Pedro lifted a 50-kg sack of rice and put it on top of his head. How much power does Pedro have if he was able to lift the sack in 1 second?

a. 1000 J/s

b. 9000 J/s

c. 100 J/s

d. 900 J/s

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determine the magnitude and direction of electric field due to the point of 4.0 to the left of a point charge of -2.5nc

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How are a gravitational and an electric field similar?

A gas with a constant pressure of 150 kPa expands from a volume of 0.76 m³ to a volume of 0.92 m³. How much work does the gas do?

A stationary proton is accelerated through a potential difference of 83.5 kV. What speed did the proton acquire?

Suppose that each headlight of a car uses 3 A and that the driver accidentally left the headlights on. How long will it take for a 12 V battery rated 80 Ah to be fully discharged?