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2 years ago

5

John shot a bullet from his rifle with a speed of 650 m/s. How much time is needed for the bullet to strike a target 3900 m away

?

1 answer:

7nadin3 [17]2 years ago

8 0

Answer:

6 seconds

Explanation:

Just divide 3900 by 650 to get the amount of time.

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A ball with a horizontal speed of 1.0m/s rolls off a bench 2.0 m high. (a) how long will the ball take to reach the floor? (b) h

bixtya [17]

The motion of the ball is a composition of two motions:
- on the x (horizontal) axis, it is a uniform motion with initial velocity $v_x = 1.0 m/s$
- on the y (vertical) axis, it is a uniformly accelerated motion with acceleration $g= 9.81 m/s^2$

(a) to solve this part, we just analyze the motion on the vertical axis. The law of motion here is
$y(t) = h - \frac{1}{2} gt^2$
By requiring y(t)=0, we find the time t at which the ball reaches the floor:
$h- \frac{1}{2}gt^2=0$
$t= \sqrt{ \frac{2h}{g} }= \sqrt{ \frac{2\cdot 2.0 m}{9.81 m/s^2} }=0.64 s$

(b) for this part, we can analyze only the motion on the horizontal axis. To find how far the ball will land, we must calculate the distance covered on the x-axis, x(t), when the ball reaches the ground (so, after a time t=0.64 s):
$x(t) = v_x t = (1.0 m/s)(0.64 s)=0.64 m$

4 0

3 years ago

Object A has mass mA = 9 kg and initial momentum vector pA,i = < 20, -6, 0 > kg · m/s, just before it strikes object B, wh

love history [14]

Answer:

$p= kg m/s$

Explanation:

Momentum is a vector quantity that represents the "amount of motion" of an object.

Mathematically, the momentum of an object is given by

$p=mv$

where

m is the mass of the object

v is the velocity

Since momentum is a vector, it also has a direction, which is the same as the velocity.

Therefore, if we have two objects, the total momentum of the two objects will be obtained from the vector sum of the individual momenta of the two objects.

In this problem we have:

$p_A= kg m/s$ is the momentum of object A

$p_B = kg m/s$ is the momentum of object B

Therefore, the total momentum of objects A and B can be obtained by adding each components of A to the corresponding component of B, so:

$p_x = 20 +6 = 26 kg m/s\\p_y = -6 +6 = 0 kg m/s\\p_z = 0 + 0 = 0 kg m/s$

So the total initial momentum is

$p= kg m/s$

6 0

2 years ago

What term best describes the geologic event taking place in the above illustration?

grigory [225]

u lying you made me get it wrong, for ya'll out there who want the real answer is sea floor spreading

8 0

2 years ago

Read 2 more answers

Helga [31]

Answer:

Follows are the solution to the given question:

Explanation:

For point a:

$T= 2\pi \sqrt{\frac{m}{k}}\\\\k = \frac{4 \pi^2 m}{T^2}\\\\= \frac{4 \times (3.14)^2 \times 3}{2^2}\\\\=29.578 \ \frac{N}{m}\\\\$

For Point b:

$E=\frac{1}{2} m a^2 w^2\\\\$

$=\frac{1}{2} \times m \times a^2 \times \frac{4\pi^2}{T^2}\\\\=\frac{1}{2} \times 3 \times (0.15)^2 \times \frac{4\times 3.14^2}{2^2}\\\\=0.332 \ J$

For Point C:

$V_{max}= a w$

$= (0.15) \times \frac{2\pi}{T}\\\\= (0.15) \times \frac{2\times 3.14}{2}\\\\=0.471 \frac{m}{s}$

For point D:

$X= a \sin (wt+ \phi)\\\\0.91=0.15 \sin(\frac{2\pi}{T} \times t+\phi)\\\\0.91=0.15 \sin(\frac{2\times 3.14}{2} \times 0.5+\phi)\\\\0.60 = \sin(3.14 \times 0.5+\phi)\\\\0.60 = \sin(1.57+\phi)\\\\1.57 +\phi =\sin^{-1} 60^{\circ}\\\\1.57 +\phi = 36.86^{\circ}\\\\=35.29^{\circ}\\\\So, X=15 \sin(3.14t+35.29^{\circ}) \ cm$

5 0

2 years ago

1. Una pelota rueda hacia la derecha siguiendo una trayectoria en línea recta de modo que recorre una distancia de 10m en 5 s ,

devlian [24]

Answer:

https://youtu.be/ymHHdoCGJOU

8 0

2 years ago