Would a pair of scissors with really long blades and a short handle be practical? Why or why not?

A girl rides her scooter to school, a total distance of 4.5km. She has to slow down twice to cross busy streets, but overall the

Whitepunk [10]

Answer:

6.93 km/h

Explanation:

To calculate her average speed, we need the "speed" formula, which is:

average speed = distance / time

You plug in your numbers and it will give you the answer.

Speed = 4.5km/0.65hr

= 6.923 km/h

8 0

3 years ago

Read 2 more answers

What is dark energy?

olga2289 [7]

Explanation:

Dark Energy. Dark Energy is a hypothetical form of energy that exerts a negative, repulsive pressure, behaving like the opposite of gravity. It has been hypothesised to account for the observational properties of distant type Ia supernovae, which show the universe going through an accelerated period of expansion

6 0

3 years ago

A physicist drives through a stop light. When he is pulled over, he tells the police officer that the Doppler shift made the red

Alik [6]

Answer:

Speed of physicist car is 0.036c or 1.08 x 10⁷ m/s .

Explanation:

Doppler Effect is defined as the change in frequency or wavelength of the wave as the source or/and observer moving away or towards each other.

In this case, the Doppler effect equation in terms of wavelength is :

$\lambda_{s} = \lambda_{o}\sqrt{\frac{1-\frac{v}{c} }{1+\frac{v}{c} } }$ ......(1)

Here $\lambda_{s}$ is source wavelength, $\lambda_{o}$ is observed wavelength, v is speed of the observer and c is the speed of light.

Given :

Source wavelength, $\lambda_{s}$ = 660 nm = 660 x 10⁻⁹ m

Observed wavelength, $\lambda_{0}$ = 555 nm = 555 x 10⁻⁹ m

Substitute these values in the equation (1).

$555\times10^{-9} } = 660\times10^{-9} \sqrt{\frac{1-\frac{v}{c} }{1+\frac{v}{c} } }$

$\sqrt{\frac{1-\frac{v}{c} }{1+\frac{v}{c} } } = 0.84$

${\frac{1-\frac{v}{c} }{1+\frac{v}{c} } } = (0.84)^{2} = 0.7056$

$1-\frac{v}{c}=0.7056+0.7056\frac{v}{c}$

$\frac{v}{c}=\frac{0.2944}{8.056}$

$v = 0.036c=0.036\times3\times10^{8}$

v = 1.08 x 10⁷ m/s

8 0

3 years ago

As an object falls:

alex41 [277]

Answer:

c it is not accelerating on it's on but gravity pulls it there for velocity increases.

5 0

2 years ago

Which type of plate boundary or zone would be most likely to lead to above-ground volcanic activity?

Anna007 [38]

Answer:

Convergent plate boundary

Explanation:

The convergent plate boundary refers to the type of boundary where two plates move towards each other. Due to this type of motion, there forms a subduction zone, where the denser plate subducts below the lighter plate. This zone of subduction is commonly identified by the presence of a deep and narrow V-shaped depression which is commonly known as the oceanic trench.

When the subducting plate enters into the region of the asthenosphere, the rocks melt and mix with the magma. This magma is then pushed upward due to the force exerted by the convection current that forms in the mantle, and further reaches the over-riding plate and eventually give rise to the formation of volcanoes and volcanic/island arcs.

Thus, this type of plate boundary is responsible for the formation of above-ground volcanic activities.

6 0

2 years ago