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
kondor19780726 [428]
3 years ago
12

A cartoon shows two friends watching an unoccupied car in free fall after it has rolled off a cliff. one friend says to the othe

r "It goes from zero to sixty miles per hour in about three seconds." is this statement correct?
Physics
2 answers:
Alona [7]3 years ago
6 0
The acceleration of gravity is 32.2 ft/sec^2.
After 3 seconds of free fall, the car is falling at 96.6 ft/sec.

60 mph is 88 ft/sec.

Let's look at it in two ways:

==> 96.6 is 9.8% greater than 88 .

==> It takes the car (88/32.2)=2.73 seconds to reach 60 mph. 3 is 9.8% greater than 2.73 .

Either way you look at it, the rough number is within 10% of the real number. That's plenty close enough to say that they're "about" the same.

It really depends on what the friends mean when they say "about". As an engineer, my personal feeling is that anything less than 10% off is a beautiful match.

enyata [817]3 years ago
3 0
1 mile = 1609 meters.60 miles = 96 540 meters.1 hour = 3 600 seconds.
Then:The velocity V = 96 540 / 3600 ≈ 26.8 m/s
Acceleration of free falla = V/t = 26.8/3 ≈ 8.9 m/c².
But it should be (excluding air resistance of 9.8 m/s².
Answer: the statement is wrong!




You might be interested in
What do you understand by family health?<br>​
AleksandrR [38]

Answer:

Family health provides, besides the cure of disease, various activities and programs in prevention, rehabilitation, and health promotion for all members of families/households. pls mark me branilest

3 0
3 years ago
Read 2 more answers
A person throws a baseball from height of 7 feet with an initial vertical velocity of 50 feet per second. Use the vertical motio
Gnoma [55]

Answer:

3.25 seconds

Explanation:

It is given that,

A person throws a baseball from height of 7 feet with an initial vertical velocity of 50 feet per second. The equation for his motion is as follows :

h=-16t^2+vt+s

Where

s is the height in feet

For the given condition, the equation becomes:

h=-16t^2+50t+7

When it hits the ground, h = 0

i.e.

-16t^2+50t+7=0

It is a quadratic equation, we find the value of t,

t = 3.25 seconds and t = -0.134 s

Neglecting negative value

Hence, for 3.25 seconds the baseball is in the air before it hits the ground.

6 0
3 years ago
Read 2 more answers
Does the horizontal distance d travelled by the ball depend on the height of release? If it does depend on the height, what is t
elena-s [515]

Answer:

Explanation:

Yes , the horizontal distance travelled by the ball will depend upon the height of release .

When a ball is thrown at some angle from a height , it has two components , the vertical component and horizontal component . The ball goes in horizontal direction due to its horizontal component . Its vertical component has no role to play .  But the horizontal range covered by the body thrown

depends upon the duration of time in which it remains in air . The longer it remains in air , the greater distance it can cover horizontally .

Horizontal distance covered = t x horizontal velocity

If V be the velocity of throw and Vx be its horizontal component

Horizontal distance covered = t x Vx

Now t depends upon the height . If height rises , time of fall will increase so horizontal distance covered will increase .

If h be the height from which the body is thrown , Vy be the vertical upward component of initial velocity

from the relation

s = ut + 1/2 at²

h = - Vy t  + 1/2 at²

As h increases , t will increase and therefore horizontal distance covered will increase. If the ball has only  horizontal velocity initially , Vy = 0

h = 1/2 gt²

t = \sqrt{\frac{2h}{g} }

Horizontal distance covered  = t x Vx

= \sqrt{\frac{2h}{g} } \times  V_x

From this expression also

Horizontal distance covered is proportional to \sqrt{h} .

7 0
3 years ago
Acording to Newton’s second law of motion if a rigid body of unchanging mass is observed accelerating what must be happening
blondinia [14]

A force is being applied to the mass.

6 0
3 years ago
Read 2 more answers
What is x-rays ? and how it's formed ?​
tia_tia [17]

X - rays are highly penetrating electromagnetic radiations that are formed when the cathode rays strikes a dense metal.

It has many characteristics such as :

  • bears no charge.

  • travels with the speed of light.

  • can ionize gases.
3 0
2 years ago
Other questions:
  • A 0.020-kg bullet traveling at a speed of 300 m/s embeds in a 1.0-kg wooden block resting on a horizontal surface. The block sli
    14·1 answer
  • The planet Jupiter’s mean orbital radius is 5.2025 AU’s. what is the period of Jupiter in earth years?
    10·1 answer
  • Light of wavelength 600 nm illuminates a diffraction grating. The second order maximum is at an angle of 65 degrees. a) List you
    6·1 answer
  • A speed skater moving to the left across frictionless ice at 8.0 m/s hits a 5.0-m-wide patch of rough ice. She slows steadily, t
    12·1 answer
  • An elevator starts from rest with a constant. upward acceleration andmoves 1m in the first. 1.8 s. A passenger in the elevator i
    10·1 answer
  • Help??????????????????????????
    10·1 answer
  • An object buoyant force and wieght arent the smae thing
    5·1 answer
  • The equation below can be used to calculate a change in gravitational potential energy. What units must be used for h? Give the
    15·1 answer
  • he electric motor of a model train accelerates the train from rest to 0.720 m/s in 29.0 ms. The total mass of the train is 840 g
    15·1 answer
  • A small box is held in place against a rough vertical wall by someone pushing on it with a force directed upward at 27 ∘ above t
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!