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ArbitrLikvidat [17]
3 years ago
14

Simon is riding a bike at 12 km/h away from his friend Keesha. He throws a ball at 5 km/h back to Keesha, who is standing still

on a sidewalk. How fast would Keesha say the ball is traveling?
Physics
1 answer:
pychu [463]3 years ago
3 0
So there are different ways this could be solved. I'll do try to explain it the way I was taught... 

Simon is riding his bike at 12 km/hr relative to the sidewalk, away from where Keesha is.

Simon throws the ball at Keesha, at 5 km/hr. 

Keesha sees the ball approaching her at (12-5) = 7 km/hr relative to the ground to her. 

Therefore the answer is: 7 km/hr


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A series circuit is composed of two resistors:
WITCHER [35]
<h3>Answer:</h3>

1.3 Amps

<h3>Explanation:</h3>

<u>We are given;</u>

A circuit with resistors, R1 and R2

R1 = 7 Ω

R2 = 11 Ω

Voltage = 24 V

We are required to calculate the current in the circuit.

<h3>Step 1: We need to find the effective resistance.</h3>

When resistors are arranged in series, the effective resistance is calculated by;

Rt = R₁ + R₂ + R₃ + ..........Rₙ

Therefore;

Total resistance = 7 + 11

                          = 18 Ω

<h3>Step 2: Calculate the current in the circuit</h3>

From the ohm's law;

V = IR

Rearranging the formula;

I = V/R

Thus;

I = 24 V ÷ 18 Ω

 = 1.333 Amps

= 1.3 Amps

Thus, the current in the circuit is 1.3 Amps

7 0
3 years ago
A lever is being used to move a heavy stone from a garden. The stone weighs 250 newtons. The board used as a lever is 6 meters l
DerKrebs [107]

Answer:

Force = 125 [N]

Explanation:

In the attached image we can see a sketch of the lever system.

And if we make a sum of moments at the point O equal to zero (0).

In the equation showed in the image, we can determinate the force that we need

7 0
3 years ago
Design an experimental set up to show that white light is made up of different colours of light​
DaniilM [7]

Answer:

Issac Newton was the first to use a glass prism to obtain the spectrum of sunlight. He tried to split the colours of the spectrum of white light further by using another similar prism. However, he could not get any more colours. He then placed a second identical prism in an inverted position with respect to the first as shown.

This allowed all the colours of the spectrum to pass through the second prism. He found a beam of white light emerging from the other side of the second prism. This observation gave Newton the idea that the sunlight is made-up of seven colours.

Explanation:

6 0
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Why do elements in the same group or column of the periodic table have similar properties? A. They have the same number of proto
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3 0
4 years ago
Two toroidal solenoids are wound around the same form so that the magnetic field of one passes through the turns of the other. S
dedylja [7]

The concept that we need here to give a proper solution is mutual inductance.

The mutual inductance  is given by the expression

M=\frac{N\Phi}{I}

Where,

I = current

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I=6.6A

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M = \frac{450*350*10^{-2}}{6.60}

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Therefore the flux in Solenoid 1 is 9*10^{-3}Wb

8 0
3 years ago
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