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
Yuliya22 [10]
3 years ago
6

A 7.91g bullet is fired into a 1.52-kg ballistic pendulum initially at rest and becomes embedded in it. The pendulum subsequentl

y rises a vertical distance of 6.89 cm. What was the initial speed of the bullet?
a. 0.38 km/s
b. 0.44 km/s
c. 0.50 km/s
d. 0.54 km/s
e. 0.024 km/s
Physics
1 answer:
Stella [2.4K]3 years ago
8 0

Answer:

D

Explanation:

By law of conservation of momentum:

momentum before collision = momentum after collision

m_{1} u_1 + m_2 u_2  = m_1 v_1 + m_2  v_2\\ m_1 = mass of bullet\\u_1 = initial speed of bullet\\m_2 = mass of pendulum\\u_2 = initial speed of pendulum\\v_1 = final speed of bullet\\v_2 = final speed of pendulum

Initial speed of bullet is unknown whereas initial speed of pendulum will be zero as it was at rest.

Final speed of bullet and pendulum will be equal as bullet is embedded in pendulum and both moves together a vertical distance of 6.89cm.

Using third equation of motion:

2 a S = v_{f}^2  - v_{i}^2

where:

a = -g = acceleration due to gravity = 9.8 m/s^2 ( for vertical motion)\\S = h = 6.89cm = Vertical height or distance it covers\\v_f = final speed = 0 (after covering 6.89cm)\\v_i = initial speed (unknown)

Thus by placing values v_i = 1.1620 m/s

this speed will be final speed of collision for the calculation of initial speed of bullet.

Putting values:

(7.91) * x + (1.52*10^3) * 0 = (7.91 + 1.52*10^3) * 1.162\\7.91 x = 1775.431\\x = 224m/s

This 224m/s = 0.224Km/s which is closest to D

You might be interested in
How to light prodeced by nature
frutty [35]
Natural sources of light include our sun and other stars, where the source of energy is nuclear energy (recall that the moon does not produce light but merely reflects sunlight), lightning, where the source is electrical, and fire, where the energy source is chemical.
4 0
3 years ago
4. What is the acceleration of a rock if the net
HACTEHA [7]

Answer:

0.75 m/s²

Explanation:

Newton's second law:

∑F = ma

3 N = (4 kg) a

a = 0.75 m/s²

8 0
4 years ago
A 115-turn circular coil of radius 2.71 cm is immersed in a uniform magnetic field that is perpendicular to the plane of the coi
tester [92]

Answer:

80.6 mV

Explanation:

Parameters given:

Number of turns, N = 115

Radius of coil, r = 2.71 cm = 0.0271m

Time taken, t = 0.133s

Initial magnetic field, Bin = 50.1 mT = 0.0501 T

Final magnetic field, Bfin = 90.5 mT = 0.0905 T

Induces EMF is given as:

EMF = [(Bfin - Bin) * N * A] / t

EMF = [(0.0905 - 0.0501) * 115 * pi * 0.0271²] / 0.133

EMF = (0.0404 * 115 * 3.142 * 0.0007344) / 0.133

EMF = 0.0806 V = 80.6 mV

3 0
3 years ago
How long does it take light to travel 850 km in a vacuum? Answer in ms.(Express your answer to two significant figures.)
poizon [28]

Answer:

0.002833 sec

Explanation:

Speed of light in vacuum is 3\times 10^{8}m/sec

Given distance = 850 km = 850×1000=850000 m

We have to calculate the time that light take to travel the distance 850 km

Time T=\frac{distance }{speed}=\frac{850000}{3\times 10^8}=2.833\times 10^{-3}sec

So the time taken by light to travel 850 km is 0.002833 sec

5 0
3 years ago
What number is between 2000 and 2500
Kitty [74]
If its just a number 2,300 is an answer 
6 0
3 years ago
Other questions:
  • A grindstone of radius 4.0 m is initially spinning with an angular speed of 8.0 rad/s. The angular speed is then increased to 12
    6·1 answer
  • If the distance between two masses is tripled, the gravitational force between changes by a factor of
    11·1 answer
  • ٠Light bulb A is rated at 60 W and light bulb B is rated at 100 W. Both are designed to operate at 110 V. Which statement is cor
    6·1 answer
  • Juliana walks 45 meters East, 45 meters south and 45 meters north. What is her resultant displacement?
    12·1 answer
  • The current in a hair dryer measures 20.0 amps. The resistance of the hair dryer is 6 ohms. What is the voltage?
    14·1 answer
  • Lynn rubs a balloon with a piece of wool, which causes the balloon to pick up some of the electric charges from the wool. Lynn t
    9·2 answers
  • g Two planets are in circular orbits around a star of with unknown mass. One planet is orbiting at a distance r1=150×106 km and
    5·2 answers
  • Octane (C8H18) is burned with dry air. The volumetric analysis of the products on a dry basis is as below. (Fig. 15–12) Determin
    13·1 answer
  • Please answer fast ————-
    15·1 answer
  • 3
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!