Ask question

Ask question

All categories

2 years ago

8

A rifle that shoots bullets at 471 m/s is to be aimed at a target 46.4 m away. If the center of the target is level with the rif

le, how high above the target must the rifle barrel be pointed so that the bullet hits dead center?

1 answer:

Genrish500 [490]2 years ago

7 0

Answer:

The equation that will express this result os

h = 0 = vy t - 1/2 g t^2 so the net height traveled by the bullet is zero

vy t = 1/2 g t^2

vy = 1/2 g t

vy = 1/2 * 9.8 * t you could use -9.8 to indicate vy and g are in different directions

tx = sx/ vx = 46.4 / 471 = .0985 sec time to travel up and down to original height

th = .0985 / 2 = .0493 sec time to reach maximum height

vy = g ty = 9.8 * .0493 sec = .483 m/s initial vertical speed

Sy = vy t - 1/2 g t^2 = .483 * .0493 - 1.2 9.8 (.0493^^2)

Sy = .0238 - 4.9 ( .0493)^2 = .0238 - .0119 = .0119 m

Height to which bullet will rise - if the gun is aimed at this height then in .0985 seconds the bullet will fall to zero height

Check: .483 / 9.8 = .0493 time to reach zero vertical speed

total travel time = 2 * .0493 = .0986 sec

471 * .0986 = 46.4 m total distance traveled by bullet

You might be interested in

Early humans used rocks as tools to make other things as well as to construct buildings. Why was it better for them to use rocks

babymother [125]

Wood isn't as tough as rock. Wood also breaks down in weather and cracks under pressure. Plus rocks were more accessible.

6 0

3 years ago

Read 2 more answers

during a baseball game you are running home and slide into home plate. However you come up short and you are tagged out. Which f

vovangra [49]

Answer:1 because

Explanation: it’s pointing to the earth and gravity

Pulls things down to earth

3 0

2 years ago

What is the relation between the gravitational force acting between any two bodies object with their masses and the distance bet

LenaWriter [7]

Answer:

The strength of the gravitational force between two objects depends on two factors, mass and distance. the force of gravity the masses exert on each other. ... increases, the force of gravity decreases. If the distance is doubled, the force of gravity is one-fourth as strong as before.

7 0

3 years ago

vampirchik [111]

Answer:

I don't know why you are asking me?

5 0

2 years ago

A baseball, which has a mass of 0.685 kg., is moving with a velocity of 38.0 m/s when it contacts the baseball bat duringwhich t

Evgen [1.6K]

Answers:

a) $65.075 kgm/s$

b) $10.526 s$

c) $61.82 N$

Explanation:

<h3>a) Impulse delivered to the ball</h3>

According to the Impulse-Momentum theorem we have the following:

$I=\Delta p=p_{2}-p_{1}$ (1)

Where:

$I$ is the impulse

$\Delta p$ is the change in momentum

$p_{2}=mV_{2}$ is the final momentum of the ball with mass $m=0.685 kg$ and final velocity (to the right) $V_{2}=57 m/s$

$p_{1}=mV_{1}$ is the initial momentum of the ball with initial velocity (to the left) $V_{1}=-38 m/s$

So:

$I=\Delta p=mV_{2}-mV_{1}$ (2)

$I=\Delta p=m(V_{2}-V_{1})$ (3)

$I=\Delta p=0.685 kg (57 m/s-(-38 m/s))$ (4)

$I=\Delta p=65.075 kg m/s$ (5)

<h3>b) Time </h3>

This time can be calculated by the following equations, taking into account the ball undergoes a maximum compression of approximately $1.0 cm=0.01 m$ :

$V_{2}=V_{1}+at$ (6)

$V_{2}^{2}=V_{1}^{2}+2ad$ (7)

Where:

$a$ is the acceleration

$d=0.01 m$ is the length the ball was compressed

$t$ is the time

Finding $a$ from (7):

$a=\frac{V_{2}^{2}-V_{1}^{2}}{2d}$ (8)

$a=\frac{(57 m/s)^{2}-(-38 m/s)^{2}}{2(0.01 m)}$ (9)

$a=90.25 m/s^{2}$ (10)

Substituting (10) in (6):

$57 m/s=-38 m/s+(90.25 m/s^{2})t$ (11)

Finding $t$ :

$t=1.052 s$ (12)

<h3>c) Force applied to the ball by the bat </h3>

According to Newton's second law of motion, the force $F$ is proportional to the variation of momentum $\Delta p$ in time $\Delta t$ :

$F=\frac{\Delta p}{\Delta t}$ (13)

$F=\frac{65.075 kgm/s}{1.052 s}$ (14)

Finally:

$F=61.82 N$

6 0

3 years ago

Read 2 more answers