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
Tomtit [17]
3 years ago
8

A car going 72.0 km/h (20.0 m/s) slows down to 36.0 km/h (10.0 m/s) in 5.00 seconds. Calculate the acceleration in

Physics
1 answer:
Nimfa-mama [501]3 years ago
3 0

Answer:

\boxed{\sf Acceleration \ (a) = -2 \ m/s^2}

Given:

Initial velocity (u) = 20 m/s

Final velocity (v) = 10 m/s

Time taken (t) = 5 seconds

To Find:

Acceleration (a) of the car

Explanation:

From equation of motion we have:

\boxed{ \bold{v = u + at}}

By substituting value of v, u & t in the equation we get:

\sf \implies 10 = 20 + 5a \\  \\  \sf \implies 5a + 20 = 10 \\  \\  \sf \implies 5a = 10 - 20 \\  \\  \sf \implies 4a =  - 10 \\  \\  \sf \implies a =  -  \frac{10}{5}  \\  \\  \sf \implies a =  - 2 \: m {s}^{ - 2}

\therefore

Acceleration (a) of the car = -2 m/s²

You might be interested in
A 20 g ball of clay traveling east at 4.5 m/s collides with a 45 g ball of clay traveling north at 2.0 m/s. You may want to revi
german

Answer:

The ball travels with a speed of 1.96 m/s in a North East direction

Explanation:

Based on the law of conservation of linear momentum, we have that

m_{1}v_{1}+m_{2}v_{2}=(m_{1}+m_{2})v

Since this problem involves motion in both the x and y coordinates, we will solve it in the separate coordinates, and then find the resultant as our answer.

Momentum in the x- direction

in the x direction, v_{2}= 0. this makes m_{2}v_{2}=0

hence we have

20\times4.5=65v_{x}

v_{x}=1.385m/s

Momentum in the y- direction

in the y direction, v_{1}= 0. this makes m_{1}v_{1}=0

hence we have

45\times2.0=65v_{y}

v_{y}=1.385m/s

The resultant of the two vectors can be found using Pythagoras' theorem

v=\sqrt{1.385^{2}+1.385^{2}} =1.959

The direction of the resultant vector is found as

Tan^{-1}(\frac{1.385}{1.385})=45degrees

Hence the ball moves with a velocity of 1.96m/s in a North East direction

7 0
3 years ago
Which of the following substances is covalently bonded? A. KF B. H2S C. CaCl2 D. SO2
poizon [28]
The answer is c for that question
6 0
4 years ago
Read 2 more answers
Pls help ASAP
12345 [234]

Answer:

a. 4.733 × 10⁻¹⁹ J = 2.954 eV b i. yes ii. 0.054 eV = 8.651 × 10⁻²¹ J

Explanation:

a. Find the energy of the incident photon.

The energy of the incident photon E = hc/λ where h = Planck's constant = 6.626 × 10⁻³⁴ Js, c = speed of light = 3 × 10⁸ m/s and λ = wavelength of light = 420 nm = 420 × 10⁻⁹ m

Substituting the values of the variables into the equation, we have

E = hc/λ

= 6.626 × 10⁻³⁴ Js × 3 × 10⁸ m/s ÷ 420 × 10⁻⁹ m

= 19.878 × 10⁻²⁶ Jm  ÷ 420 × 10⁻⁹ m

= 0.04733 × 10⁻¹⁷ J

= 4.733 × 10⁻¹⁹ J

Since 1 eV = 1.602 × 10⁻¹⁹ J,

4.733 × 10⁻¹⁹ J = 4.733 × 10⁻¹⁹ J × 1 eV/1.602 × 10⁻¹⁹ J = 2.954 eV

b. i. Is this energy enough for an electron to leave the atom

Since E = 2.954 eV is greater than the work function Ф = 2.9 eV, an electron would leave the atom. So, the answer is yes.

ii. What is its  maximum energy?

The maximum energy E' = E - Ф = 2.954 - 2.9

= 0.054 eV

= 0.054 × 1 eV

= 0.054 × 1.602 × 10⁻¹⁹ J

= 0.08651  × 10⁻¹⁹ J

= 8.651 × 10⁻²¹ J

7 0
3 years ago
What does the person in front of the ambulance experience?
kow [346]

A higher frequency. I just got this answer on usa test prep.

6 0
3 years ago
What causes the phenomena?
Murrr4er [49]

Answer:

Most pneumonia occurs when a breakdown in your body's natural defenses allows germs to invade and multiply within your lungs.

Explanation:

7 0
3 years ago
Other questions:
  • Airbrakes on some trucks have how many second lag time with for the engage properly?
    15·1 answer
  • A star having a luminosity 10,000 times that of the sun and a surface temperature only two-thirds of that of the sun, or 4,000k,
    7·1 answer
  • A block of foam has a mass of 10 g, a volume of 60 cm3, and a length of 30 cm. What is the density of the foam? (If necessary, r
    5·2 answers
  • An apple weighs at 1N. the net force on the apple when it is in free fall is?
    11·1 answer
  • What does it mean standard unit?​
    13·1 answer
  • Determine the length of a wind instrument, assuming that it is modeled as a closed tube and that the lowest sound that it can pl
    5·1 answer
  • A car with speed v and an identical car with speed 2v both travel the same circular section of an unbanked road. If the friction
    7·1 answer
  • An object of mass 5kg travels in the positive direction with a speed of 1ms1ms. The object collides with a second object that ex
    10·1 answer
  • Calculate the work done by an applied force of 76.0 N on a crate for the following. (Include the sign of the value in your answe
    14·1 answer
  • Write 3 – 4 sentences to describe the kinetic and potential energy of a particle and how the two terms are related.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!