PHYSICS *30 POINTS + BRAINLIEST ANSWER*

A car accelerates from rest at 3.6 m/s 2 . How much time does it need to attain a speed of 5 m/s?

Olenka [21]

car starts from rest

$v_i = 0$

final speed attained by the car is

$v_f = 5 m/s$

acceleration of the car will be

$a = 3.6 m/s^2$

now the time to reach this final speed will be

$t = \frac{v_f - v_i}{a}$

$t = \frac{5 - 0}{3.6}$

$t = 1.39 s$

so it required 1.39 s to reach this final speed

6 0

3 years ago

An ambulance driver traveling at 31.0 m/s (69.3 mph) honks his horn as he sees a motorist ahead on the highway traveling in the

IrinaVladis [17]

Answer:

fo = 378.52Hz

Explanation:

Using Doppler effect formula:

$f'=\frac{C-Vb}{C-Va}*fo$

where

f' = 392 Hz

C = 340m/s

Vb = 20m/s

Va = 31m/s

Replacing these values and solving for fo:

fo = 378.52Hz

4 0

2 years ago

A bicycle is heading West. It goes 5000m in 500s what's its velocity

dybincka [34]

There are several information's of immense importance already given in the question. Based on the given information's the answer to the question can easily be determined.
Distance covered by the bicycle = 5000 meter
Time taken by the bicycle to reach the distance = 500 second.
Velocity of the bicycle = Distance / Time taken
= 5000/500 meter/second
= 50 meter/second
So the velocity of the bicycle is 50 meter per second. I hope the procedure is clear enough for you to understand. In future you can always use this procedure for solving similar problems.

8 0

2 years ago

I need help ASAPP

Tresset [83]

Answer: For the first part the answer is Radio Waves and the second part’s answer is gamma ray.

6 0

3 years ago

An electron has a charge of 1.602 X 10-19.coulomb. When two electrons are separated by 1.2 X 10-9m, what force will they exert o

amid [387]

Answer:

The force they will exert on each other is 1.6*10⁻¹⁰ N

Explanation:

The electromagnetic force is the interaction that occurs between bodies that have an electric charge. When the charges are at rest, the interaction between them is called the electrostatic force. Depending on the sign of the interacting charges, the electrostatic force can be attractive or repulsive. The electrostatic interaction between charges of the same sign is repulsive, while the interaction between charges of the opposite sign is attractive.

Coulomb's law is used to calculate the electric force acting between two charges at rest. This force depends on the distance "r" between the electrons and the charge of both.

Coulomb's law is represented by:

$F=k*\frac{q1*q2}{r^{2} }$

where:

F = electric force of attraction or repulsion in Newtons (N). Like charges repel and opposite charges attract.
k = is the Coulomb constant or electrical constant of proportionality.
q = value of the electric charges measured in Coulomb (C).
r = distance that separates the charges and that is measured in meters (m).

In this case:

k= 9*10⁹ $\frac{N*m^{2} }{C^{2} }$
q1= 1.602*10⁻¹⁹ C
q2= 1.602*10⁻¹⁹ C
r= 1.2*10⁻⁹ m

Replacing:

$F=9*10^{9} \frac{N*m^{2} }{C^{2} }*\frac{1.602*10^{-19} C*1.602*10^{-19} C}{(1.2*10^{-9} )^{2} }$

and solving you get:

F=1.6*10⁻¹⁰ N

<u><em>The force they will exert on each other is 1.6*10⁻¹⁰ N</em></u>

3 0

2 years ago