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
quester [9]
3 years ago
12

You drop a rock from rest out of a window on the top floor of a building, 25.0 m above the ground. When the rock has fallen 4.90

m, your friend throws a second rock straight down from the same window. You notice that both rocks reach the ground at the exact same time. What was the initial velocity of the rock that your friend threw? (Assume upward is the positive direction and downward is negative. Indicate the direction with the sign of your answer.)
Physics
1 answer:
ryzh [129]3 years ago
3 0

Answer:13.86 m/s

Explanation:

Given

building height=25 m

another rock is thrown after first rock has fallen 4.90 m

time taken by first rock to cover 4.90 m

s=ut+\frac{gt^2}{2}

4.90=0+\frac{9.81\times t^2}{2}

t=1 s

time taken by first rock to reach at bottom

s=ut+\frac{gt^2}{2}

25=0+\frac{9.81\times t^2}{2}

t=2.25 sec

Now second rock will take 1 s less than first rock

time for second rock=1.25 s

s=ut+\frac{gt^2}{2}

25=u\times 1.25+\frac{9.81\times 1.25^2}{2}

u\times 1.25=25-\frac{9.81\times 1.25^2}{2}

u=13.86 m/s

You might be interested in
An object is thrown with velocity v from the edge of a cliff above level ground. Neglect air resistance. In order for the object
musickatia [10]

Answer:

(C) greater than zero but less than 45° above the horizontal

Explanation:

The range of a projectile is given by R = v²sin2θ/g.

For maximum range, sin2θ = 1 ⇒ 2θ = sin⁻¹(1) = 90°

2θ = 90°

θ = 90°/2 = 45°

So the maximum horizontal distance R is in the range 0 < θ < 45°, if θ is the angle above the horizontal.

4 0
3 years ago
Read 2 more answers
What statement illustrates how engineering has influenced society
Ghella [55]
OPTION A if it’s for Plato
3 0
3 years ago
A rabbit runs 4.4 m across a lawn, stops, then runs 2.2 m back in the opposite direction. What is the rabbit’s displacement from
Alla [95]

Answer:

it is 2.2 m

Explanation:

because he goes back 2.2 m so 4.4 minus 2.2 equals 2.2

6 0
3 years ago
Which scientist began organizing elements into the periodic table?
Gre4nikov [31]

Answer:

B. Dmitri Mendeleev

Explanation:

he invented it

3 0
3 years ago
Read 2 more answers
A package was determined to have a mass of 5.7 kilograms. What's the force of gravity acting on the package on earth? A. 37.93 N
Kryger [21]
Force of gravity = Mass x Gravitational force
Fg=mg
Fg = (5.7)(9.8)
Fg= 55.86 N
7 0
3 years ago
Read 2 more answers
Other questions:
  • A 0.500 kg rock is whirled in a vertical circle of a radius 0.60 m . the velocity of the rock at the bottom of the swing is 4.0
    8·1 answer
  • What is an analogy that describes the process of electron carriers?
    7·2 answers
  • What are the formulas to calculate acceleration
    10·2 answers
  • In the earth-moon system the moon orbits the earth. What is the "centripetal" force causing the moon to stay in orbit around the
    14·1 answer
  • Which liquid has a higher density; shampoo or rubing (isopropyl) alcohol?
    6·1 answer
  • The medical model of abnormality states that psychological disorders are __________.
    11·2 answers
  • A ____ mirror will diverge light rays. <br> a. convex <br> b. plane <br> c. concave
    9·2 answers
  • On a cello, the string with the largest linear density (1.44 x 10-2 kg/m) is the C string. This string produces a fundamental fr
    9·1 answer
  • Would u rather/ be in avengers or x-men
    5·1 answer
  • Which element is the main component of<br> steel and the most widely used of all metals
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!