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
Firdavs [7]
3 years ago
15

A 4.45 g object moving to the right at 18.6 cm/s makes an elastic head-on collision with an 8.9 g object that is initially at re

st.
18.6 cm/s
4.45 g
8.9 g
Find the velocity of the first object immediately after the collision. The acceleration of gravity is 9.8 m/s 2 . Answer in units of cm/s.
Physics
1 answer:
scoundrel [369]3 years ago
4 0

Answer:

v₁f = -6.2 cm/s

Explanation:

  • Assuming no external forces acting during the collision, total momentum must be conserved, as follows:

        m_{1} *v_{1o} = m_{1}* v_{1f} + m_{2}* v_{2f}

  • As the collision is elastic, total kinetic energy must be conserved also:

       \frac{1}{2}*m_{1}*v_{1o}^{2} = \frac{1}{2}*m_{1}*v_{1f} ^{2} + \frac{1}2}*m_{2}*v_{2f}^{2}

  • From the givens, we know that m₂ = 2* m₁
  • Replacing in the above equations, rearranging both sides and simplifying, we can find the following expression for v₁f:

       v_{1f} = \frac{-m_{1} }{3*m_{1}} *v_{1o} =\frac{-v_{1o}}{3} = -\frac{18.6 cm/s}{3} = -6.2 cm/s

  • v₁f = -6.2 cm/s (which means that it bounces back after the collision).
You might be interested in
Identify the following physical quantities as scalars or vectors.
34kurt
Position displacement velocity acceleration are vectors and the rest are scalars
6 0
4 years ago
Read 2 more answers
Milky Way Galaxy: Position of Solar System within this galaxy (where is earth)
ale4655 [162]
Do you mean what order the Earth is in? The planets in order from closest to farthest from the sun are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto is technically just a dwarf planet but I'll include it anyways.
8 0
4 years ago
Read 2 more answers
Traveling 221 miles from Boston Back Bay Station to NYC Penn Station takes 3 hours
Nostrana [21]

Answer:

Approximately 116\; \text{miles} for the train from Boston to NYC Penn Station.

Approximately 105\; \text{miles} for the train from NYC Penn Station to Boston.

Explanation:

Convert minutes to hours:

\begin{aligned}t(\text{BOS $\to$ NYC}) &= 3\; {\text{hour}} + 40\; \text{minute} \times \frac{1\; {\text{hour}}}{60\; \text{minute}} \\ &=\left(3 + \frac{2}{3}\right)\; \text{hour}\\ &= \frac{11}{3}\; \text{hour} \end{aligned}.

\begin{aligned}t(\text{NYC $\to$ BOS}) &= 4\; {\text{hour}} + 5\; \text{minute} \times \frac{1\; {\text{hour}}}{60\; \text{minute}} \\ &= \frac{49}{15}\; \text{hour} \end{aligned}.

Calculate average speed of each train:

\begin{aligned}v(\text{BOS $\to$ NYC}) &= \frac{s}{t}\\ &= \frac{221\; \text{mile}}{\displaystyle \frac{11}{3}\; \text{hour}} \\ &= \frac{663}{11}\; \text{mile} \cdot \text{hour}^{-1}\end{aligned}.

\begin{aligned}v(\text{NYC $\to$ BOS}) &= \frac{s}{t}\\ &= \frac{221\; \text{mile}}{\displaystyle \frac{49}{15}\; \text{hour}} \\ &= \frac{2652}{49}\; \text{mile} \cdot \text{hour}^{-1}\end{aligned}

Assume that it takes a time period of t for the trains to pass by each other after departure. Distance each train travelled would be:

s(\text{NYC $\to$ BOS}) = v(\text{NYC $\to$ BOS})\, t.

s(\text{BOS $\to$ NYC}) = v(\text{BOS $\to$ NYC})\, t.

Since the trains have just passed by each other, the sum of the two distances should be equal to the distance between the stations:

v(\text{NYC $\to$ BOS})\, t + v(\text{BOS $\to$ NYC})\, t = 221\; \text{mile}.

Rearrange and solve for t:

(v(\text{NYC $\to$ BOS}) + v(\text{BOS $\to$ NYC}))\, t = 221\; \text{mile}.

\begin{aligned}t &= \frac{221\; \text{mile}}{v(\text{NYC $\to$ BOS}) + v(\text{BOS $\to$ NYC})} \\ &= \frac{221\; \text{mile}}{\displaystyle \frac{663}{11}\; \text{mile} \cdot \text{hour}^{-1} + \frac{2652}{49}\; \text{mile} \cdot \text{hour}^{-1}} \\ &= \frac{539}{279}\; \text{hour}\end{aligned}.

Distance each train travelled in t = (539 / 279)\; \text{hour}:

\begin{aligned}s(\text{BOS $\to$ NYC}) &= v\, t \\ &= \frac{663}{11}\; \text{mile} \cdot \text{hour}^{-1} \times \frac{539}{279}\; \text{hour} \\ &\approx 116\; \text{mile}\end{aligned}.

\begin{aligned}s(\text{NYC $\to$ BOS}) &= v\, t \\ &= \frac{2652}{49}\; \text{mile} \cdot \text{hour}^{-1} \times \frac{539}{279}\; \text{hour} \\ &\approx 105\; \text{mile} \end{aligned}.

8 0
2 years ago
You are approaching a railroad crossing with no warning devices and are unable to see 400 feet down the tracks in one direction.
azamat

Answer: The speed limit is 15 mph when you come within 100 feet of a railroad crossing and you cannot see the tracks for 400 feet in both directions. You may go faster than 15 mph if the crossing is controlled by gates, a warning signal, or a flagman.

Explanation: hope this helps

4 0
2 years ago
Read 2 more answers
The specific heat capacity of sea water is 4100 J/Kg°C and the boiling point of 100.6 °C. (i) Calculate the energy required to r
maw [93]

Answer:

334.314 (kJ)

Explanation:

1) the formula for the required energy is: Q=c*m(Bp-t), where c - 4100 J/kg*C; m - 0.9 kg; Bp - 100.6 C; t - 10 C.

2) according to the formula above:

Q=4100*0.9*(100.6-10)=41*9*906=334314 (J).

6 0
3 years ago
Other questions:
  • What force keeps our atmosphere from floating out into space?
    12·2 answers
  • Which types of changes observe the law of conservation of mass?
    8·1 answer
  • _____ are used to support engineering and technical users who perform heavy mathematical computing, computer-assisted design (CA
    8·1 answer
  • Technician A says that engine parts should be be cleaned before a thorough test can be done to detect cracks. Technician B says
    11·1 answer
  • a lemon with mass 0.3 kg falls out of a tree from a height of 1.8 m. How much mechanical energy does the lemon have just before
    12·2 answers
  • Who was copernicus and what have he done for science?
    15·1 answer
  • Calculate the location xcm of the center of mass of the Earth-Moon system. Use a coordinate system in which the center of the Ea
    14·1 answer
  • Help with these please someone?
    12·1 answer
  • A metre rule is used to measure the length of a piece of string in a certain experiment. It is found to be 20 cm long to the nea
    6·1 answer
  • A cannonball is fired perfectly horizontally from the top of a 210 m tall cliff. It is fired with an initial velocity of 50 m/s.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!