Physics, 04.07.2019 14:10 nathangirnet

How long will it take a shell fired from a cliff at an initial velocity of 800 m/s at an angle 30 degrees below the horizontal to reach the ground 150m below?

Answers: 1

Show answers

Answers

Answer from: abby986

0.373 seconds. First, calculate the initial vertical velocity of the shell. 800sin(30) = 800*0.5 = 400 m/s Now the formula for the distance traveled is d = 400 m/s * T + 0.5A T^2 Substituting known values gives. 150 = 400 m/s * T + 0.5*9.80m/s^2 T^2 150 = 400 m/s * T + 4.9 m/s^2 T^2 Arrange as a quadratic formula 0 = 400 m/s * T + 4.9 m/s^2 T^2 - 150 4.9 m/s^2 T^2 + 400 m/s * T - 150 = 0 Now solve for T using the quadratic formula with a=4.9, b=400, and c=-150 The calculated value is 0.373 seconds. Is this value reasonable? Let's check. The initial downward velocity is 400 m/s. So 150/400 = 0.375 seconds. Since the actual time will be a bit less due to acceleration by gravity and since the total time is so short, there won't be much acceleration due to gravity, the value of 0.373 is quite reasonable.

Answer from: 0spholbrooks

The shell will take about 0.34 seconds to reach the ground.

Step 1

T is given as 800 m/s. The factors that would impact time are gravity and angle.

The factor of gravity (g) is a constant given as = 9.81. Any object on earth will accelerate at the speed of 9.81 meters per second if they are in a free fall.

Hence, T = 800Sin(30°) / g = 800 * 0.5

This is equals 400/9.81 = 40.773 or 40.78 seconds.

Step 2

Given that the vertical velocity of the shell is zero because it is accelerating at an angle towards the earth, it will rise at an average speed that can be computed as:

1/2 (800sin30°) = 1/2 * 400 = 200m/s for Tsec and arise of H which is 8,156m.

Step 3

The shell having risen falls from rest at the height given above.

S therefore, = 150 +H, that is 150 + 8,156m. This is equals to 8,306m.

Step 4

Next, we compute for the Kinematics equation of distance in relation to time (t) where the initial speed is 0.

S = 1/2(gt)²

thus 8,306 = 0.5 * 9.81*t² with elementary cross multiplication and the and the squaring of both sides, we have

t = $\sqrt{1693}$

t= 41.14608 which is approximately 41.12 seconds.

Because the time taken for the shell to rise and then to fall to the ground is the sum of T and t. the time taken to fall or the time taken for the shell to travel towards to the ground is:

t - T = 41.12 - 40.78

= 0.34 seconds

See the link below for more about Velocity:

link

Answer from: Quest

hi there!

out of the two, (b) precision would be more reasonable. however, both a and b could be pretty reasonable.

-awesomerepublic : )

Answer from: Quest

Wavelength divides in half and speed stays the same.

Another question on Physics

Physics, 21.06.2019 19:40

Abird sitting high in a tree is an example of what type of wnergy

Answers: 2

Answer

Physics, 22.06.2019 11:30

Which of these questions might a character ask if the conflict is man versus self? a. which path should i take to better myself? b. which boulder will be too heavy for me to carry? c. which friend is going to ditch me today? d. all of the above

Answers: 1

Answer

Physics, 22.06.2019 16:30

What is the kinetic energy of a baseball moving at a speed of 40 m/s if the baseball has mass of 0.15 kg?

Answers: 2

Answer

Physics, 23.06.2019 19:30

The number of loops in the primary coil divided by the number of loops in the secondary coil equals the voltage in the primary coil divided by the voltage in the secondary coil if the volunteer attached to the primary coil read 100 volts what would the voltmeter attached to the secondary coil read

Answers: 1

Answer

You know the right answer?

How long will it take a shell fired from a cliff at an initial velocity of 800 m/s at an angle 30 de...

Questions