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
emmainna [20.7K]
2 years ago
12

7. A car is travelling along a road at 30 ms when a pedestrian steps into the road 55 m ahead. The

Physics
1 answer:
trasher [3.6K]2 years ago
6 0

Answer: Car collide with man

Explanation:

Given

Speed of car is u=30\ m/s

Distance of the man from the car is s=55\ m

Reaction time t_r=0.5\ s

Rate of deceleration a_d=-10\ m/s^2

Distance traveled in the reaction time d_o=30\times 0.5=15\ m

Net effective distance to cover d=55-15=40\ m

Distance required to stop the car

\Rightarrow v^2-30^2=2(-10)(s)\\\Rightarrow 0-900=-20s\\\Rightarrow s=45\ m

Require distance is more than that of net effective distance. Hence, car collides with the man.

You might be interested in
Does energy or matter ever disappear? Explain.
maria [59]

Answer:

The first law of thermodynamics doesn't actually specify that matter can neither be created nor destroyed, but instead that the total amount of energy in a closed system cannot be created nor destroyed (though it can be changed from one form to another).

Explanation:

3 0
3 years ago
Read 2 more answers
Classify each of the following chemical reactions. Upper S plus upper O Subscript 2 right arrow upper S upper O subscript 2. Upp
vodka [1.7K]

Check attached image.

4 0
2 years ago
A diver springs upward from a board that is 4.40 m above the water. At the instant she contacts the water her speed is 13.5 m/s
Yakvenalex [24]

The diver has the initial velocity, both (a) magnitude is 9.8 m/s and (b) direction is  73.5°.

<h3>What is free falling?</h3>

When an object is released from rest in free air considering no friction, the motion is depend only on the acceleration due to gravity, g.

If we drop an object of mass m near the Earth surface from a height h, it has initial mechanical energy(P.E)

U =mgh

When the object strikes the ground, all the potential energy converted into kinetic energy.

K.E = 1/2mv²

where v is the speed just before hitting the ground.

A diver springs upward from a board that is 4.40 m above the water. At the instant, she contacts the water her speed is 13.5 m/s and her body makes an angle of 78.1 ° with respect to the horizontal surface of the water.

(a)

From energy conservation principle, initial and final mechanical energy are equal.

1/2mu² + mgh = 1/2mv²

where, u is the initial velocity of the diver.

u = sq rt  (v² - 2gh)

u = sq rt (13.5² - 2x9.81x4.4)

u = 9.798 m/s or 9.8 m/s

Thus, the velocity of the diver is 9.8 m/s.

(b)

The horizontal component of velocity will remain constant.

The horizontal component of acceleration is zero.

Then,

ucosθ = vcosΦ

θ = cos⁻¹ [ (13.5 x cos 78.1)/9.8 ]

θ = 73.5°

Thus, the direction of velocity is  73.5°.

Learn more about free falling.

brainly.com/question/13299152

#SPJ1

5 0
1 year ago
Give an example of something that is cyclic and non - cyclic
LiRa [457]
 a clock .. and i guess a non functioning clock ?

7 0
2 years ago
Because light travels in a straight line and casts a shadow, Isaac Newton hypothesized that light is
KonstantinChe [14]

A stream of particles

3 0
3 years ago
Other questions:
  • Two skaters begin at rest. Skater 1 has a smaller mass than Skater 2. After they push off each other,...
    15·2 answers
  • A simple machine that is a straight slanted surface is
    15·1 answer
  • Longitudinal waves have _____.
    13·2 answers
  • Imagine two people standing at placemark A and placemark E, looking at each other across the fault. Which of the following state
    7·1 answer
  • Which of the following has the strongest magnetic field? Earth, the Sun, Jupiter, a pulsar
    8·2 answers
  • What is an object doing at the moment its instantaneous acceleration is zero?
    11·1 answer
  • In a machining operation that approximates orthogonal cutting, the cutting tool has a rake angle =100 . The chip thickness ratio
    14·1 answer
  • A local AM radio station broadcasts at a frequency of 696 KHz. Calculate the energy of the frequency at which it is broadcasting
    8·1 answer
  • Anybody knows this thanks !
    10·2 answers
  • What is the geocentric angle of the earthquake focus?​
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!