Ask question

Ask question

All categories

2 years ago

6

Some people say that the “force of inertia” (and “force of momentum”) throws the passengers forward when a car brakes sharply. w

hat is wrong with this explanation

1 answer:

marishachu [46]2 years ago

5 0

the car stops, the inertia of people keeps them going. no force ... they were going before the car stopped

sudden stop = pain

gentle stop = ok

You might be interested in

A satellite is to be launched into an orbit of radius,r Show that v = 2gr, where V is the

Snezhnost [94]

Explanation:

We start by using the conservation law of energy:

$\Delta{K} + \Delta{U} = 0$

or

$\dfrac{1}{2}mv^2 - G\dfrac{mM}{r} = 0$

Simplifying the above equation, we get

$v^2 = 2G\dfrac{M}{r}$

We can rewrite this as

$v^2 = 2\left(G\dfrac{M}{r^2}\right)r$

Note that the expression inside the parenthesis is simply the acceleration due to gravity $g$ so we can write

$v^2 = 2gr$

where $v$ is the launch velocity.

6 0

2 years ago

A 50kg meteorite moving at 1000 m/s strikes Earth. Assume the velocity is along the line joining Earth's center of mass and the

zysi [14]

As per the question, the mass of meteorite [ m]= 50 kg

The velocity of the meteorite [v] = 1000 m/s

When the meteorite falls on the ground, it will give whole of its kinetic energy to earth.

We are asked to calculate the gain in kinetic energy of earth.

The kinetic energy of meteorite is calculated as -

$Kinetic\ energy\ [K.E]\ =\frac{1}{2} mv^2$

$=\frac{1}{2}50kg*[1000\ m/s]^2$

$=\frac{1}{2}50* 10^{6}\ J$

$=25*10^6\ J$

Here, J stands for Joule which is the S.I unit of energy.

$Hence,\ the\ kinetic\ energy\ gained\ by\ earth\ is\ 25*10^6\ J$

4 0

2 years ago

Read 2 more answers

A jet is circling an airport control tower at a distance of 20.6 km. An observer in the tower watches the jet cross in front of

lesya [120]

Answer:

197.76 m

Explanation:

r = Radius of the path = 20.6 km = $20.6\times 10^3\ m$

$\theta$ = The angle subtended by moon = $9.6\times 10^{-3}\ rad$

Distance traveled is given by

$s=r\times\theta$

$\Rightarrow s=20.6\times 10^3\times 9.6\times 10^{-3}$

$\Rightarrow s=197.76\ m$

The distance traveled by the jet is 197.76 m

8 0

2 years ago

Assume that the polymer material has a constant refractive index of 1.5. For light of 600nm wavelength at normal incidence, what

yaroslaw [1]

Answer:

Minimum thickness will be 100 nm

Explanation:

We have given refractive index is n = 1.5

Wavelength of the light incidence $\lambda$ = 600 nm

We have to find the smallest thickness of the film so that there will be minimum light reflect

For minimum thickness of non reflecting film

$t=\frac{\lambda }{4n}$ , here t is thickness, $\lambda$ is wavelength and n is refractive index

Putting all values $t=\frac{600}{4\times 1.5}=100nm$

So minimum thickness will be 100 nm

8 0

2 years ago

A sonar pulse sent out by a boat arrives back after 4 seconds. If the speed of sound in water is 1600m/s, how deep is the water?

Varvara68 [4.7K]

Answer:

the boat would be deeped by 3200 m

Explanation:

Given that

The boat arrives back after 4 seconds

And, the speed of the sound in water is 1,600 m/s

We need to find out how much deep is the water

So,

As we know that

Distance = ( speed × time) ÷ 2

Here we divided by 2 because the boat arrives back

= (1600 × 4) ÷ 2

= 3200 m

Therefore the boat would be deeped by 3200 m

7 0

2 years ago