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2 years ago

Question 8 of 25

Physics

1 answer:

GuDViN [60]2 years ago

7 0

Answer:

A. They use X-rays that penetrate most objects.

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Two physics students are arguing about superconductors and their discovery, Jeffe says that he can use a

Liono4ka [1.6K]

Answer:

B on edge2020-2021

Explanation:

5 0

2 years ago

A double insulated drill ____. A. has two ground wires to insure proper grounding B. generally has a plastic case with the elect

Len [333]

Answer:

Option B is correct.

A double insulated drill generally has a plastic case with the electrical connections and motor insulated within the tool

Explanation:

A double insulated drill's design in real life has plastic casing as the insulator & it wouldn't be a drill without its motor now, would it!?

8 0

2 years ago

A disk of a radius 50 cm rotates at a constant rate of 100 rpm. What distance in meters will a point on the outside rim travel d

Dmitry [639]

Answer:

the distance in meters traveled by a point outside the rim is 157.1 m

Explanation:

Given;

radius of the disk, r = 50 cm = 0.5 m

angular speed of the disk, ω = 100 rpm

time of motion, t = 30 s

The distance in meters traveled by a point outside the rim is calculated as follows;

$\theta = \omega t\\\\\theta = (100 \frac{rev}{\min} \times \frac{2\pi \ rad}{1 \ rev} \times \frac{1\min}{60 s} ) \times (30 s)\\\\\theta = 100 \pi \ rad\\\\d = \theta r\\\\d = 100\pi \ \times \ 0.5m\\\\d = 50 \pi \ m = 157.1 \ m$

Therefore, the distance in meters traveled by a point outside the rim is 157.1 m

6 0

3 years ago

1. A step-up transformer increases 15.7V to 110V. What is the current in the secondary as compared to the primary? Assume 100 pe

Serjik [45]

1. $I_2 = 0.14 I_1$

Explanation:

We have:

$V_1 = 15.7 V$ voltage in the primary coil

$V_2 = 110 V$ voltage in the secondary coil

The efficiency of the transformer is 100%: this means that the power in the primary coil and in the secondary coil are equal

$P_1 = P_2\\V_1 I_1 = V_2 I_2$

where I1 and I2 are the currents in the two coils. Re-arranging the equation, we find

$\frac{I_2}{I_1}=\frac{V_1}{V_2}=\frac{15.7 V}{110 V}=0.14$

which means that the current in the secondary coil is 14% of the value of the current in the primary coil.

2. 5.7 V

We can solve the problem by using the transformer equation:

$\frac{N_p}{N_s}=\frac{V_p}{V_s}$

where:

Np = 400 is the number of turns in the primary coil

Ns = 19 is the number of turns in the secondary coil

Vp = 120 V is the voltage in the primary coil

Vs = ? is the voltage in the secondary coil

Re-arranging the formula and substituting the numbers, we find:

$V_s = V_p \frac{N_s}{N_p}=(120 V)\frac{19}{400}=5.7 V$

5 0

2 years ago

Thermodynamics

Marizza181 [45]

Answer:

A heat engine is a device that converts internal energy into work. Internal energy is increased by the addition of heat. The efficiency of a heat engine is a measurement of how efficiently it works. Efficiency compares the amount of useful energy extracted from a process to the total energy input. The heat engine will be more efficient if the percentage is higher.

Explanation:

5 0

2 years ago