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
Zina [86]
3 years ago
6

Imagine a rock is dropped from the top of a tall building.After 2 seconds of falling the rock is instantaneous speed In approxim

ately 20m/s
Physics
1 answer:
Fantom [35]3 years ago
8 0

This is True.

Explanation:

initial velocity= Vi=0

final velocity= V

acceleration due to gravity= 9.8 m/s²

using the kinematic equation V= Vi+gt

V=0+(9.8)(2)

V= 19.6 m/s which is approximately equal to 20 m/s

Thus after 2 seconds, the instantaneous speed of the rock is approximately 20 m/s.

You might be interested in
What can fall but never get hurt
Vladimir [108]

It’s either snow or rain if it’s a riddle sort of.

4 0
3 years ago
Read 2 more answers
The windshield of a car has a total length of arm and blade of 9 ​inches, and rotates back and forth through an angle of 93degre
Sergio039 [100]

Answer:

The area of the portion of the windshield cleaned by the 7-in wiper blade is 62.49 in²

Explanation:

Given

Length of blade = 9 inches

Angle of rotation = 93°

We're to calculate the area of the portion of the windshield cleaned by the 7​-in wiper​ blade?

We'll solve this by using area of a sector.

Area of a sector = ½r²θ

where θ is in radians.

So, angle of rotation (93°) must first be converted to radians

Converting 93º to radians, we get 31π/60

The area of the region swept out by the wiper blade = (area of the sector where r = 9 and

θ = 31π/60) - (area of the sector where r = (9-7) and θ = 31π/60).

We're making use of 9-7 because that region is outside the boundary of the 7in blade

So Area = ½*9²*31π/60 - ½*2²*31π/60

Area = ½*31π/60(9²-7²)

Area = 31π/120 * (81 - 49)

Area = 31π/120 * 32

Area = 992π/120

Area = 62.49151386765697 in²

Area ≈ 62.49 in²

Hence, the area of the portion of the windshield cleaned by the 7-in wiper blade is 62.49 in²

5 0
3 years ago
Read 2 more answers
Spring #1 has a force constant of k, and spring #2 has a force constant of 2k. Both springs are attached to the ceiling. Identic
Gre4nikov [31]

Answer:

The ratio of the energy stored by spring #1 to that stored by spring #2 is 2:1

Explanation:

Let the weight that is hooked to two springs be w.

Spring#1:

Force constant= k

let x1 be the extension in spring#1

Therefore by balancing the forces, we get

Spring force= weight

⇒k·x1=w

⇒x1=w/k

Energy stored in a spring is given by \frac{1}{2}kx^{2} where k is the force constant and x is the extension in spring.

Therefore Energy stored in spring#1 is, \frac{1}{2}k(x1)^{2}

                                                              ⇒\frac{1}{2}k(\frac{w}{k})^{2}

                                                              ⇒\frac{w^{2}}{2k}

Spring #2:

Force constant= 2k

let x2 be the extension in spring#2

Therefore by balancing the forces, we get

Spring force= weight

⇒2k·x2=w

⇒x2=w/2k

Therefore Energy stored in spring#2 is, \frac{1}{2}2k(x2)^{2}

                                                              ⇒\frac{1}{2}2k(\frac{w}{2k})^{2}

                                                              ⇒\frac{w^{2}}{4k}

∴The ratio of the energy stored by spring #1 to that stored by spring #2 is \frac{\frac{w^{2}}{2k}}{\frac{w^{2}}{4k}}=2:1

4 0
3 years ago
What's the mass show the work?
Alja [10]
You do this one just like the other one that I just solved for you.

For this one ...

The density of the object is 2.5 gm/cm³.
We know that every cm³ of it we have contains 2.5 gm of mass.
We have to find out how many cm³ we have.

The question tells us:  We have  2.0 cm³.

Each cm³ of space that the object occupies contains 2.5 gm of mass.

So the 2.0 cm³ that we have contains (2 x 2.5 gm) = 5 gms.
That's the mass of our object.
6 0
3 years ago
Ben's famliy lives in Florida. His dad wants to cut down the cost of the electricity bill, and he has decided to install some la
AlexFokin [52]

Answer:

the answer would be solar energy, because solar panels are used for solar energy and they also cut back on your bill

5 0
3 years ago
Read 2 more answers
Other questions:
  • The maximum lift-to-drag ratio of the World War I Sopwith Camel was 7.7. If the aircraft is in flight at 5000 ft when the engine
    10·1 answer
  • Give several examples of a mechanism, machine or system that has two
    15·1 answer
  • According to modern atomic theory, it is nearly impossible to determine an electron’s exact
    6·1 answer
  • a train is moving 35m/s to the east. it speeds up to 42 m/s east over the course of 40 seconds. what is the trains acceleration?
    13·1 answer
  • The speed of sound through oxygen at 0°C is 316 meters per second. The speed of sound through solid copper is 5,010 meters per s
    6·2 answers
  • A projectile is launched straight upward at 50 m/s. Neglecting air resistance its speed upon returning to its starting point is:
    10·1 answer
  • BRAINLIEST WILL BE GIVEN!!!!! After communicating the information you requested above, he pushes the sled a total distance of 50
    6·1 answer
  • If a permanent magnet picks up a steel paper clip, the paper clip also
    7·2 answers
  • If I could snap my fingers and move Earth to an orbital distance at 9 AU, what would happen to the strength of the Sun's gravita
    11·1 answer
  • Select the correct answer.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!