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4 years ago

Explain why average velocity in one dimension can be positive or negative.

2 answers:

6 0

<span>One dimensional velocity is based upon a straight line. For example: You can only go forwards or backwards. You assign one direct (lets say forward) to be positive. So if you move backwards, you are technically moving in a negative direction </span>

Softa [21]4 years ago

3 0

Imagine an object is moving in one dimension on a number line, and for this we'll say that the numbers on the line are a metre apart. If the object moves from 2 m to 7 m, the change in position is 7-2=+5 metres. But if the object moves back from 7 m to 2 m, the change in position is 2-7=-5 metres. since $velocity = \frac{change in position}{time}$ , and time is always positive, velocity will be positive in one direction and negative in the other direction.

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Calculate the power of a crane if it lifts a load of 2400N through a height of 10m in 15 seconds.Also express the power in horse

dem82 [27]

Answer:

Explanation:

The power of the crane can be found by using the formula

$p = \frac{f \times d}{t} \\$

f is the Force

d is the distance

t is the time taken

From the question we have

$p = \frac{2400 \times 10}{15} = \frac{24000}{15} \\$

We have

power = 1600 W

But 1 W = 0.0013 hp

So 1600 = 2.08 hp

We have the final answer as

Hope this helps you

3 0

4 years ago

A spacecraft in the shape of a long cylinder has a length of 100 m, and its mass with occupants is 1 480 kg. It has strayed too

maks197457 [2]

Answer:

2352645198509.9604 m/s²

Explanation:

G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²

M = Mass of black hole = $90\times 1.989\times 10^{30}\ kg$

$R_{f}$ = 10000+100 m

$R_{sb}$ = Distance between the nose and the center of the black hole = 10000 m

The difference in the gravitational field in this system is given by

$\Delta F=\dfrac{GMm}{R_{f}^2}-\dfrac{GMm}{R_{sb}^2}\\\Rightarrow \Delta g=GM\left(\frac{1}{R_f^2}-\frac{1}{R_{sb}^2}\right)\\\Rightarrow g=6.67\times 10^{-11}\times 90\times 1.989\times 10^{30}\left(\frac{1}{(10000+100)^2}-\frac{1}{10000^2}\right)\\\Rightarrow \Delta g=-2352645198509.9604\ m/s^2$

The acceleration is 2352645198509.9604 m/s²

4 0

3 years ago

Elaine and her bike have a combined mass of 50 kg. in a bicycle race, Elaine uses the pedals to create a forward force of 75 N.

yarga [219]

If the friction and air resistance was 75N and Elaine was traveling with a force of 75N the forces would cancel out. Elaine's bike would not be moving and all the forces would be balanced

6 0

4 years ago

4.A 13.6 kg bag of dog food is held 1.25 m above the ground. Calculate the

Tanzania [10]

Answer:

PE = mgh = 13.6(9.81)(1.25) = 166.77 ≈ 167 J

Explanation:

5 0

3 years ago

What would the potential of a standard hydrogen electrode (s.h.e.) be under the given conditions? [h+]=0.70 mph2=2.4 atmt=298 k?

Andru [333]

Constant = 8.314JK⁻¹mol⁻¹
T is for temperature which is 298K
Faraday constant value is 96500C/mol
n is the number of electrons which are transferred in the reaction.
Ecell = E₀cell - RT/nFiN [cathode]/[anode]
Ecell = E₀cell - RT/nF In [PH₂]/[H⁺]²
Ecell = 0.00-8.314 JK⁻¹ mol⁻¹ × 298k/ 2× 96500C/mol In [2.4atm]/ 0.70]²
Ecell = 0.00 - 0.0129 In (2.59)
Ecell = 0.00 - 0.0129 × 0.951
Ecell = -0.0122V
∴Ecell is = -o.0122v

7 0

3 years ago