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
Aliun [14]
4 years ago
10

You and your friend Peter are putting new shingles on a roof pitched at 21∘. You're sitting on the very top of the roof when Pet

er, who is on the edge of the roof, 5.1 mm away, asks you for the box of nails. Rather than carry the 2.3 kgkg box of nails down to Peter, you decide to give the box a push and have it slide down to him. If the coefficient of kinetic friction between the box and the roof is 0.53, with what speed should you push the box to have it gently come to rest right at the edge of the roof?
Physics
1 answer:
Marat540 [252]4 years ago
8 0

Answer:

3.69 m/s

Explanation:

Forces :

mgsin Θ - mumgcosΘ = ma  

g x sinΘ  - mu x g x cosΘ  = a

9.8 x sin 21 - 0.53 x 9.8 x cos 21 = a

a = -1.337 m/s²

so you have final velocity = 0 m/s

initial velocity = ? m/s

Given d = 5.1 m

By kinematics

vf² = vo² + 2ad

0 = vo² + 2 x -1.337*5.1

vo = 3.69 m/s

You might be interested in
The maximum pressure most organisms can survive is about 1000 times the atmospheric pressure. Only small, simple organisms such
Schach [20]

Answer:

h = 10000 m

Explanation:

The pressure applied at a depth of the liquid is given by:

P =ρgh

where,

P = Maximum Pressure to Survive = (1000)(Atmospheric Pressure)

P = (1000)(101325 Pa) = 1.01 x 10⁸ Pa

ρ = Density of sea water = 1025 kg/m³

g = 9.8 m/s²

h = maximum depth to survive = ?

Therefore,

1.01 x 10⁸ Pa = (1025 kg/m³)(9.8 m/s²)h

h = (1.01 x 10⁸ Pa)/(1025 kg/m³)(9.8 m/s²)

<u>h = 10000 m</u>

6 0
3 years ago
Which structure reduces friction between joints?
Roman55 [17]

Answer:

The cartilage is the structure that reduces friction between joints.

Explanation:

Cartilage is the tissue between the bone joints. They are composed of several membranes and cellular groups. One of them called synovial membrane which provides lubricant to the edges of tissue that are touched by the bones. Reducing the friction and absorbing it so the body can move without obstacles.

3 0
3 years ago
Many pigeons live near Martyn’s air conditioning vents. Martyn isn’t able to clean the vents properly, and they often contain dr
Furkat [3]

Answer:

B) Aerosol

The particles from the pigeon droppings are likely to be transmitted from the air vents directly into Martyn's respiratory system

3 0
3 years ago
How much potential energy does a 40-N medicine ball gain when it is lifted 5 m?
777dan777 [17]
We know, Potential Energy = Force * Height
Here, F = 40 N
h = 5 m

Substitute their values, 
U = 40 * 5
U = 200 J

In short, Your Answer would be Option A

Hope this helps!
6 0
3 years ago
 An ultrasound pulse used in medical imaging has a frequency of 5 MHz and a pulse width of 0.5 us. Ap- proximately how many osci
podryga [215]

At the frequency of 5 MHz, the period of the oscillations is 1/5meg. That's a period of 1/5 microsecond.

There are 5 full cycles in one full microsecond, and there are 2.5 full cycles in a 0.5 us pulse.

You'll have to decide for yourself how damped a pulse of 2.5 cycles is, because the parameters of the definition are corrupted in the question.

4 0
3 years ago
Other questions:
  • When two objects of different masses, different temperatures, and different sizes are placed in thermal contact, energy will alw
    7·1 answer
  • What do all heterotrophs have in common?
    13·1 answer
  • PLEASE ANSWER FAST I WILL GIVE BRAINLIEST
    5·2 answers
  • What is the atomic bomb equivalent to a 7.0 earthquake
    6·1 answer
  • PLEASE ANSWER ASAP
    11·1 answer
  • What happens to most of the light waves that strike a clear pane of glass? O A. absorption B. diffraction O C. reflection O D. t
    10·2 answers
  • If the focal length of a concave mirror is 18cm, find its radius of curvature.
    14·1 answer
  • Which of the following equations illustrates the law of conservation of<br> matter?
    9·1 answer
  • PLEASE HELP 100 POINTS!!!!!
    5·2 answers
  • If light photons are massless then why are they attracted by black holes?​
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!