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expeople1 [14]
3 years ago
7

A rock falls from a high cliff and hits the ground in 6.5 seconds. What is the final velocity?

Physics
1 answer:
scoray [572]3 years ago
5 0

Answer:

122.5m

Explanation:

Basic kinematics, negating drag and assuming ideal conditions, we use the equation:

d=vi*t+1/2*a*t^2

Since vi is 0 (we know this because you’re dropping it, not throwing it)…

…and the only acceleration acting on it is gravity, a=9.8 m/s^2…

…we get

d=1/2(9.8)(5)^2

Some quick mental math tells us that this is about 125 m.

Plugging it in, we find it to be 122.5 m.

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What is a terrestrial planet?
NISA [10]

Answer: Hi!

A terrestrial planet is composed of a solid substance like rock or earth. A few examples are our planet, Earth, and the red planet, Mars. These are the planets that are the closest to the sun. There are four terrestrial planets in total. The only known terrestrial planet that has life, however, is our own, Earth! Earth has the perfect conditions for supporting life forms.

Hope this helps!

3 0
3 years ago
What happens to the current in a circuit if the resistance triples? If the voltage triples?
Sauron [17]
(Example 1 ) 
<span>If the Voltage that furnishes the current is an ideal (no internal resistance) Voltage source. Then; </span>

<span>V/R = i </span>
<span>V/2R = i/2 If external resistance doubles, current reduced to 1/2 of original value </span>
<span>V/3R = i/3 If external resistance triples, current reduced to 1/3 of original value </span>

<span>(Example 2) </span>
<span>But if the Voltage that furnishes the current is a practical [contains an internal resistance (Ri)] Voltage source. Then the current is a function of the Voltage source`s internal resistance, which does not double nor triple, plus the external resistance which is being doubled and tripled. </span>

<span>V/(R + Ri) = i </span>
<span>V/(2R + Ri) = greater than i/2 but less than I. </span>
<span>V/(3R + Ri) = greater than i/3 but less than i/2</span>
7 0
3 years ago
A uniform steel girder of weight 22KN and of length 12m is lifted off the ground at one end by means of a crane. When the raised
Keith_Richards [23]

Answer:

Explanation:

For free body diagram see attached sheet .

W is weight of steel girder acting at the middle point of its length . T is tension in the cable .

OB = √ ( 12² - 2² )

= 11.83 m .

OC = 11.83 / 2 = 5.915 m

Taking moment of tension T and weight W about point O

W x OC = T x OB

22 x 5.915 = T x 11.83

T = 22 x 5.915 / 11.83

= 11 kN

Considering forces acting in vertical direction and equating forces in opposite direction

T + R = W

R = W - T

= 22 - 11 = 11 KN

So force of grinder on the ground = R

= 11 KN.

8 0
2 years ago
If a electrician measures the current of a circuit to be 100 Amps and the circuit is only designed to have a current of 80 Amps,
Talja [164]

There are too many batteries in the circuit, which increased the emf of the circuit and in turn increased the current in the circuit.

<h3>Current in the circuit</h3>

The current in the circuit is determined by applying Ohms law as shown below;

V = IR

where;

  • I is the current
  • V is the voltage
  • R is the resistance

I = V/R

At a constant resistance of the circuit, the current in a circuit will increase when the emf of the circuit increases.

Thus, we can conclude that, there are too many batteries in the circuit, which increased the emf of the circuit and in turn increased the current in the circuit.

Learn more about current in circuit here: brainly.com/question/13195529

6 0
2 years ago
An emergency relief plane is dropping a care package from a plane to a group of medical personnel working for a relief agency in
ipn [44]

Answer:

The altitude of the plane is 379.5 m.

Explanation:

Initial horizontal velocity, u = 59.1 m/s

Horizontal distance, d = 521 m

let the time taken by the packet to cover the distance is t.

Horizontal distance = horizontal velocity x time

521 = 59.1 x t

t = 8.8 s

let the vertical height is h .

Use second equation of motion in vertical direction.

h = u t  + 0.5 gt^2\\\\h = 0 + 4.9 \times 8.8\times8.8\\\\h= 379.5 m

7 0
2 years ago
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