Most sodium atoms have an atomic mass of 23, but a few have atomic

SCORPION-xisa [38]

Answer:

caves are mainly formed by water or in some other cases limestone.

6 0

2 years ago

A quarterback throws a football toward a receiver with an initial speed of 20 m/s at an angle of 30∘ above the horizontal. At th

lana66690 [7]

Answer:

a) In order to catch the ball at the level at which it is thrown in the direction of motion.

b)Speed of the receiver will be 7.52m/s

Explanation:

Calculating range,R= Vo^2Sin2theta/g

R= (20^2×Sin(2×30)/9.8 = 35.35m

Let receiver be(R-20) = 35.35-20= 15.35m

The horizontal component of the ball is:

Vox= Vocostheta= 20× cos30°

Vox= 17.32m/s

Time taken to coverR=35.35m with 17.32m/s will be:

t=R/Vox= 35.35/17.32

t= 2.04seconds

b)Speed required to cover 15.35m at 2.04seconds

Vxreciever= d/t = 15.35/2.04 = 7.52m/s

7 0

3 years ago

Read 2 more answers

Which car is harder to stop and why?

kondor19780726 [428]

Answer:

The momentum of bath cars is 40000 Ns which make the difficulty to stop each car in aspect of fprce is the same.

Explanation:

Momentum (P) =mass(m) × velocity (v)

For car A,

P = m × v = 1000 × 40 = 40000 Ns

For car B,

P = m × v = 4000 × 10 = 40000 Ns

Force (F) = Momentum change(ΔΡ)/ time taken(t)

F = ΔΡ/t

When stopping the car the momentum changes from 40000 Ns to 0

So momentum change in both cars is the same. So to stop the two cars in a given time (t) you need the same force, which means you will feel same difficulty.

8 0

3 years ago

Read 2 more answers

At what pressure will the mean free path in room-temperature (20?c) nitrogen be 1.5 m ?

kondaur [170]

In physical chemistry, the mean free path is the average distance between the atoms during collision. Its formula is

$Mean \ free \ path \ = \frac{RT}{ \sqrt{2} \pi d^{2} N_{A}P }$

where d is the diameter of the Nitrogen atom (d = 310 x 10^-7 m), Na is Avogadro's number (Na=6.022 x 10^23), R is the gas constant (8.314 J/mol-K), T is the absolute temperature (T= 20 + 273 = 293 K). Substituting the values,

$1.5 = \frac{(8.314)(293)}{ \sqrt{2} \pi (310 \ x\ 10^{-7} )^{2} (6.022 \ x\ 10^{23} )P }$
P = 6.32 x 10^-13 Pascals

6 0

3 years ago

A simple accelerometer is constructed inside a car by suspending an object of mass m from a string of length L that is tied to t

Fittoniya [83]

Answer:

Part a)

$\theta = tan^{-1}\frac{a}{g}$