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
netineya [11]
3 years ago
6

a baseball pitcher throws a fastball at 42 meters per second. if the batter is 18 meters from the pitcher, approximately how muc

h time does it take for the ball to reach the batter?
Physics
2 answers:
lapo4ka [179]3 years ago
6 0
T=D/v = 18/42 = 43 seconds
LiRa [457]3 years ago
4 0
T = distance div time = 18/42 = 3/7 seconds = 0.4 seconds

less than half of a second

You might be interested in
Automobile A and B are initially 30 m apart travelling in adjacent highway lanes at speeds VA = 14.4 km/hr., VB 23.4 km/hr. at t
marshall27 [118]

Answer:

        x = 240 m

Explanation:

This is a kinematics exercise

Let's fix our frame of reference on car A

           x = x₀ₐ+ v₀ₐ t + ½ aₐ t²

         

the initial position of car a is zero

           x = 0 + v₀ₐ t + ½ 0.8 t²

for car B

          x = x_{ob} + v_{ob} t - ½ a_b t²

     

car B's starting position is 30 m

         x = 30 + v_{ob} t - ½ 0.4 t²

at the point where they meet, the position of the two vehicles is the same

         0 + v₀ₐ t + ½ 0.8 t² = 30 + v_{ob} t - ½ 0.4 t²

let's reduce the speeds to the SI system

        v₀ₐ = 14.4 km / h (1000 m / 1 km) (1h / 3600s) = 4 m / s

        v_{ob} = 23.4 km / h = 6.5 m / s

        4 t + 0.4 t² = 30 + 6.5 t - 0.2 t²

        0.2 t² - 2.5 t - 30 = 0

        t² - 12.5 t - 150 = 0

we solve the quadratic equation

       t = \frac{12.5 \pm \sqrt{12.5^2 + 4 \ 150}  }{2}

       t = \frac{12.5 \  \pm 27.5}{2}

       t₁ = 20 s

       t₂ = -7.5 s

time must be a positive quantity so the correct result is t = 20 s

let's look for the distance

        x = 4 t + ½ 0.8 t²

        x = 4 20 + ½ 0.8 20²

        x = 240 m

8 0
2 years ago
Which of the following is formed by constructive erosion? 1. delta 2. gully 3. rill 4. glacier
lana [24]
1. Delta, is formed by constructive erosion.
7 0
3 years ago
How do molecules at warm temperatures differ from molecules at cool temperatures? Question 1 options: At warm temperatures, mole
yaroslaw [1]

Answer:

A. At warm tempetures, molecules move around more.

Explanation:

I'm at k12 and I just took the test got it right. Physical Science: Unit 2 Test

7 0
3 years ago
Read 2 more answers
The chart shows data for an object moving at a constant acceleration. Which values best complete the chart? Time (s) Velocity (m
dangina [55]

Answer:

A.

x: 0

y: 0

z: 0

Explanation:

3 0
3 years ago
Read 2 more answers
What is the speed of a wave if it has a wavelength of<br> 42 m and a frequency of 7 hertz?
Nimfa-mama [501]

Answer:

♕ \large{ \red{ \tt{Step - By - Step \: Explanation}}}

☃ \underline{ \underline{ \blue{ \large{ \tt{G \: I \: V \: E\: N}}}}} :

  • Frequency ( f ) = 7 Hertz
  • Wavelength ( λ ) = 42m

♨ \underline {\underline{ \orange{ \large{ \tt{T \: O \:  \: F \: I \: N\: D}}}} }:

  • Wave velocity ( v )

☄ \underline{ \underline{ \large{ \pink{ \tt{S\: O \: L \: U \: T\: I \: O \: N}}}}}:

✧ \red{ \boxed{ \large{ \purple{ \sf{Wave \: velocity(v) = Frequency(f) \times Wavelength(λ)}}}}}

~Plug the known values and then multiply!

↦ \large{ \tt{7  \times 42}}

↦ \boxed{ \boxed{ \large{ \bold{ \tt{294 \: m {s}^ {- 1} }}}}}

☥ \large{ \boxed{ \boxed{ \large{ \tt{Our \: Final \: Answer :  \underline{ \large{ \tt{294 \: m {s}^{ - 1}}}}}}}}}

---------------------------------------------------------------

❁ \underline{ \large{  \red{ \tt{D\: E\: T \: A \: I \: L\: E \: D \:  \: I\: N \: F \: O}}}} :

  • Frequency ( f ) : The number of complete waves , set up in a medium in one second is called frequency of the wave. The SI unit of frequency is Hertz ( Hz ). For example : if a sound wave completes 15 compressions and 15 rarefactions in one second , it's frequency is 15 Hz.

  • Wavelength ( λ ) : The distance between two consecutive troughs or crests in a transverse wave or the distance between two consecutive compressions or rarefactions in a longitudinal wave us called wavelength. It is the distance travelled by a wave in a time equal to it's time period. It's SI unit is metre ( m ).

  • Wave velocity ( v ) : The velocity with which a wave propagates in a medium is called wave velocity. It's SI unit is m/s.

# KILL : Excuses

KISS : Opportunities

MARRY : Goals

♪ Hope I helped! ♡

☂ Have a wonderful day / night ! ツ

✎ \underbrace{ \overbrace{ \mathfrak{Carry \: On \: Learning}}} ✔

▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁

4 0
3 years ago
Other questions:
  • what is the acceleration of a 20kg bike if its being pedaled in a northerly direction with constant unbalanced force of 10 nwhat
    14·1 answer
  • A carpenter is driving a 15.0-g steel nail into a board. His 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. Half
    6·1 answer
  • What is critical to being an active listener?
    11·1 answer
  • Symbion pandora has a symbiotic relationship with the Norway lobster. True False
    7·1 answer
  • Heat energy always moves from a _ _ _ place to a _ _ _ _ _ _ place. The three methods of heat transfer are?
    14·1 answer
  • Know the 4 types of communication skills describe each​
    13·1 answer
  • Two strings with linear densities of 5 g/m are stretched over pulleys, adjusted to have vibrating lengths of 0.50 m, and attache
    12·1 answer
  • A paintball is fired horizontally from a tower 45 m above the ground. If the paintball gun fires at 90 m/s… How long does it tak
    11·1 answer
  • help plz! what vibrates in following types of wave motion 1)light wave 2)sound waves 3)x-rays 4)water waves​
    14·1 answer
  • Which of the following statements about waves are true? Select all that apply.
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!