Select the correct answer. which of these is a scalar quantity? a. acceleration b. displacement c. length d. velocity

At noon on a clear day, sunlight reaches the earth\'s surface at Madison, Wisconsin, with an average power of approximately 3.00

alexira [117]

Energy of a wave:
E = nhc/λ
3000 = (n x 6.63 x 10⁻³⁴ x 3 x 10⁸)/(510 x 10⁻⁹)
n = 7.69 x 10 ²¹ photons per second per meter²
2.70 cm² = 2.70/10,000 m²
= 2.7 x 10⁻⁴
Photons per second = 7.69 x 10 ²¹ x 2.7 x 10⁻⁴
= 2.08 x 10¹⁸ photons per second

4 0

3 years ago

Signment

jeka94

Answer:

v = 5.15 m/s

Explanation:

At constant velocity, the cable tension will equal the car weight of 984(9.81) = 9,653 N

As the cable tension is less than this value, the car must be accelerating downward.

7730 = 984(9.81 - a)

a = 1.95 m/s²

kinematic equations s = ut + ½at² and v = u + at

-5.00 = u(4.00) + ½(-1.95)4.00²

u = 2.65 m/s the car's initial velocity was upward at 2.65 m/s

v = 2.65 + (-1.95)(4.00)

v = -5.15 m/s

3 0

3 years ago

An AC adapter for a telephone answering machine uses a transformer to reduce the line voltage of 120 V to a voltage of 5.00 V. T

Maksim231197 [3]

Answer:

35

Explanation:

We are given that

Initial voltage, $V_1=120 V$

Final voltage, $V_2=5 V$

Number of tuns in primary coil of the transformer, $N_p=840$

Rms current, $I_{rms}=580mA=580\times 10^{-3} A$

$1 mA=10^{-3} A$

We have to find the number of turns are there on the secondary coil.

We know that

$\frac{N_s}{N_p}=\frac{V_2}{V_1}$

Using the formula

$\frac{N_s}{840}=\frac{5}{120}$

$N_s=\frac{5}{120}\times 840=35$

Hence, there are number of turns on the secondary coil=35

8 0

3 years ago

On Mars, where air resistance is negligible, an astronaut drops a rock from a cliff and notes that the rock falls about d meters

dimulka [17.4K]

Answer:

$d_1 = 16 d$

Explanation:

As we know that initial speed of the fall of the stone is ZERO

$v_i = 0$

also the acceleration due to gravity on Mars is g

so we have

$d = v_i t + \frac{1}{2}gt^2$

now we have

$d = 0 + \frac{1}{2}g t^2$

now if the same is dropped for 4t seconds of time

then again we will use above equation

$d_1 = 0 + \frac{1}{2}g(4t)^2$

$d_1 = 16(\frac{1}{2}gt^2)$

$d_1 = 16 d$

7 0

4 years ago

Read 2 more answers

A box slides downwards at a constant velocity on an inclined surface that has a coefficient of friction uK = .58 The angle of th

mojhsa [17]

Answer: The angle of inclination is nearly 30°

Explanation:

For a body on an inclined plane, the coefficient of friction between the body and the plane is equal to the ratio of the moving force applied to the body to the frictional force acting on the body.

If uK coefficient of friction;

Fm is the moving force

R is the normal reaction on the body

Mathematically uK = Fm/R

Fm = WSin(theta)

R = Wcos(theta)

uK = Wsin(theta)/Wcos(theta)

uK = tan(theta)

theta = arctan(uK)

If uK is 0.58

theta = arctan0.58

theta = 30°

The angle of the inclined will be 30°

7 0

3 years ago