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
mina [271]
3 years ago
8

Mt. Asama, Japan, is an active volcano. In 2009, an eruption threw solid volcanic rocks that landed 1 km horizontally from the c

rater. If the volcanic rocks were launched at an angle of 40° with respect to the horizontal and landed 900 m below the crater, (a) what would be their initial velocity and (b) what is their time of flight?
Physics
1 answer:
Nata [24]3 years ago
7 0

Answer:

a) 69.3 m/s

b) 18.84 s

Explanation:

Let the initial velocity = u

The vertical and horizontal components of the velocity is given by uᵧ and uₓ respectively

uᵧ = u sin 40° = 0.6428 u

uₓ = u cos 40° = 0.766 u

We're given that the horizontal distance travelled by the projectile rock (Range) = 1 km = 1000 m

The range of a projectile motion is given as

R = uₓt

where t = total time of flight

1000 = 0.766 ut

ut = 1305.5

The vertical distance travelled by the projectile rocks,

y = uᵧ t - (1/2)gt²

y = - 900 m (900 m below the crater's level)

-900 = 0.6428 ut - 4.9t²

Recall, ut = 1305.5

-900 = 0.6428(1305.5) - 4.9 t²

4.9t² = 839.1754 + 900

4.9t² = 1739.1754

t = 18.84 s

Recall again, ut = 1305.5

u = 1305.5/18.84 = 69.3 m/s

You might be interested in
How are energy, work ang power related?
jolli1 [7]

Answer:

Work is the change in energy and power is the rate of doing work.

5 0
3 years ago
A theory is a way of explaining observations. true or false.
Natasha_Volkova [10]
I think its true. hope this helps.
5 0
3 years ago
Read 2 more answers
A helium balloon ride lifts up passengers in a basket. Assume the density of air is 1.28 kg/m3 and the density of helium in the
max2010maxim [7]

Answer:

V = 381.70 m³

Explanation:

ρ air = 1.28 kg / m³

ρ helium = 0.18 kg / m³

R = 4.5 m

Vb = 0.068 m³

mb = 123 kg

To determine the volume of helium in the balloon when fully inflated

V = 4 / 3 π * R ³

V = 4 * π / 3 ( 4.5 m )³

V = 381.70 m³

To determine the mass total

m = ρ helium * V

m = 0.18 kg / m³  * 381.70  m³

m = 68.70 kg

mt = ( 68.70 + 123 )kg

mt = 191.70 kg

3 0
3 years ago
The roller-coaster car shown in fig. 6-41 (h1 = 30 m, h2 = 12 m, h3 = 20 m), is dragged up to point 1 where it is released from
maxonik [38]
<span>Since there is no friction, conservation of energy gives change in energy is zero Change in energy = 0 Change in KE + Change in PE = 0 1/2 x m x (vf^2 - vi^2) + m x g x (hf-hi) = 0 1/2 x (vf^2 - vi^2) + g x (hf-hi) = 0 (vf^2 - vi^2) = 2 x g x (hi - hf) Since it starts from rest vi = 0 Vf = squareroot of (2 x g x (hi - hf)) For h1, no hf Vf = squareroot of (2 x g x (hi - hf)) Vf = squareroot of (2 x 9.81 x 30) Vf = squareroot of 588.6 Vf = 24.26 For h2 Vf = squareroot of (2 x 9.81 x (30 – 12)) Vf = squareroot of (9.81 x 36) Vf = squareroot of 353.16 Vf = 18.79 For h3 Vf = squareroot of (2 x 9.81 x (30 – 20)) Vf = squareroot of (20 x 9.81) Vf = 18.79</span>
7 0
3 years ago
The graph represents the reaction 2H2 + 02 32H20 as it reaches
Alex

Answer:

C and D

Explanation:

5 0
3 years ago
Read 2 more answers
Other questions:
  • A baseball is dropped off the side of a cliff. It free-falls to the ground in 8 seconds. During the third second, the ball is tr
    6·2 answers
  • Which type of energy is produced
    7·1 answer
  • 1. How is electric potential energy similar to gravitational potential energy? How is it different? Where will an electron bound
    5·1 answer
  • When calculating power what two pieces of information are needed?
    5·1 answer
  • A round loop of wire carries a current of 100 A, has a radius of 10 cm, and its normal (vector) makes an angle of 30∘ with a mag
    12·1 answer
  • ___________ is a tiny, hair-like fiber that aids in movement.
    9·1 answer
  • A book has a mass of 50 grams and an<br> acceleration of 5 m/s/s. What is the<br> force on the book?
    10·2 answers
  • A 120-kg refrigerator, 2.00 m tall and 85.0 cm wide, has its center of mass at its geometrical center. You are attempting to sli
    7·1 answer
  • what did taking measurements reveal about the velocity of the fireball? Was the fireball’s velocity constant or changing?
    13·1 answer
  • Reflect on your new experiences, what made you uncomfortable and what encouraged you. Did you learn anything new about yourself
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!