1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Dafna1 [17]
4 years ago
8

A projectile is fired vertically upwards and reaches a height of 78.4 m. Find the velocity of projection and the time it takes t

o reach its highest point.
Physics
1 answer:
Musya8 [376]4 years ago
7 0

Answer:

1.) U = 39.2 m/s

2.) t = 4s

Explanation: Given that the

height H = 78.4m

The projectile is fired vertically upwards under the acceleration due to gravity g = 9.8 m/s^2

Let's assume that the maximum height = 78.4m. And at maximum height, final velocity V = 0

Velocity of projections can be achieved by using the formula

V^2 = U^2 - 2gH

g will be negative as the object is moving against the gravity

0 = U^2 - 2 × 9.8 × 78.4

U^2 = 1536.64

U = sqrt( 1536.64 )

U = 39.2 m/s

The time it takes to reach its highest point can be calculated by using the formula;

V = U - gt

Where V = 0

Substitute U and t into the formula

0 = 39.2 - 9.8 × t

9.8t = 39.2

t = 39.2/9.8

t = 4 seconds.

You might be interested in
Consider a model of a hydrogen atom in which an electron is in a circular orbit of radius r = 5.92×10−11 m around a stationary p
DaniilM [7]

Answer:

2.068 x 10^6 m / s

Explanation:

radius, r = 5.92 x 10^-11 m

mass of electron, m = 9.1 x 10^-31 kg

charge of electron, q = 1.6 x 10^-19 C

As the electron is revolving in a circular path, it experiences a centripetal force which is balanced by the electrostatic force between the electron and the nucleus.

centripetal force = \frac{mv^{2}}{r}

Electrostatic force = \frac{kq^{2}}{r^{2}}

where, k be the Coulombic constant, k = 9 x 10^9 Nm^2 / C^2

So, balancing both the forces we get

\frac{kq^{2}}{r^{2}}=\frac{mv^{2}}{r}

v=\sqrt{\frac{kq^{2}}{mr}}

v=\sqrt{\frac{9\times 10^{9}\times1.6\times 10^{-19}\times 1.6\times 10^{-19}}{9.1\times 10^{-31}\times 5.92\times10^{-11}}}

v = 2.068 x 10^6 m / s

Thus, the speed of the electron is give by  2.068 x 10^6 m / s.

6 0
3 years ago
I need help thanks I would appreciate your in-depth explanation thanks.
svlad2 [7]

Answer:

The coin is less dense than the water thefore it can float.

Explanation:

5 0
3 years ago
Read 2 more answers
20 characters or more
andreev551 [17]

Answer:

yes 20 characters or more

Explanation:

3 0
2 years ago
A magnetic field is uniform over a flat, horizontal circular region with a radius of 1.50 mm, and the field varies with time. In
atroni [7]

Answer:

The average induced emf around the border of the circular region is 8.48\times 10^{-5}\ V.

Explanation:

Given that,

Radius of circular region, r = 1.5 mm

Initial magnetic field, B = 0

Final magnetic field, B' = 1.5 T

The magnetic field is pointing upward when viewed from above, perpendicular to the circular plane in a time of 125 ms. We need to find the average induced emf around the border of the circular region. It is given by the rate of change of magnetic flux as :

\epsilon=\dfrac{-d\phi}{dt}\\\\\epsilon=A\dfrac{-d(B'-B)}{dt}\\\\\epsilon=\pi (1.5\times 10^{-3})^2\times \dfrac{1.5}{0.125}\\\\\epsilon=8.48\times 10^{-5}\ V

So, the average induced emf around the border of the circular region is 8.48\times 10^{-5}\ V.

6 0
3 years ago
Read 2 more answers
8. What is the frequency of green light waves that have a wavelength of 5.2 x 10-7 m.? The speed of light is 3.0 x 108 m/s
o-na [289]

Answer:

f=5.76\times 10^{14}\ Hz

Explanation:

We need to find the frequency of green light having wavelength o5.2\times 10^{-7}\ m. It can be calculated as follows :

c=f\lambda\\\\f=\dfrac{c}{\lambda}\\\\f=\dfrac{3\times 10^8}{5.2\times 10^{-7}}\\\\f=5.76\times 10^{14}\ Hz

So, the required frequency of green light is equal to 5.76\times 10^{14}\ Hz.

4 0
3 years ago
Other questions:
  • Looking for some help with the left side of the table and the questions followed :)
    12·1 answer
  • In being served, a tennis ball is accelerated from rest to a speed of 42.1 m/s. The average power generated during the serve is
    6·1 answer
  • Consider a sample of helium gas in a container fitted with a piston, as pictured below. The piston is frictionless, but has a ma
    15·2 answers
  • If a conductor wire gets heated. What happens with its resistance?
    9·1 answer
  • A scooter traveling at 4 m/s rides 800 meters. For what duration of time has the scooter been traveling?
    10·2 answers
  • Calculate the minimum frequency of ultrasound (in Hz) that will allow you to see details as small as 0.193 mm in human tissue. (
    15·1 answer
  • A kΩ resistor is connected to an AC voltage source with an rms voltage of V. (a) What is the maximum potential difference across
    14·1 answer
  • Tin shears have longer handles than the scissors used to cut cloth why ​
    12·1 answer
  • Question 1 (1 point)
    9·1 answer
  • What is the total moved without regard to direction​
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!