Does the atomic number of an atom change?

A 140 g baseball is moving horizontally to the right at 35 mis when it is hit by the bat. the ball fl ies off to the le ft at 55

Anit [1.1K]

Answer:

J = 12.32kg*m/s

Explanation:

Assumptions: I'm assuming mis is m/s

Given: The baseball's mass is 140g, so convert to kg, 0.140kg. (Good rule of thumb, in physics convert grams to kilograms). It is initially traveling 35 m/s to the right.

When it hits the bat, it flies left with a velocity of 55 m/s at an angle of 25°. To reiterate:

mass = 0.140kg, Initial: 35m/s, Final: 55m/s at an angle of 25°

For this problem, we have to use the impulse equation, but before that lets break the velocity into components (It will be apparent towards the end):

The initial velocity is moving only in the horizontal direction, so:

$v_{0x} = 35 m/s$

The final velocity has an x and a y component:

$v_{fx} = 55cos(25) = 49.84692829m/s\\v_{fy} = 55sin(25) = 23.2440044m/s$

Now the equation for impulse is (dp is Δp, which is difference in momentum; dv is Δv, the difference in velocity; J is impulse):

$J = dp= m*dv$

To get Δv, we have to find the difference of velocity, that is why we broke it into components. I'm going to define right as positive and left as negative. After that, we find the velocity vector:

$dv_{x} = (35-(-49.84692829)) = 84.84692829 m/s\\dv_{y} = (0-(23.2440044)) = -23.2440044 m/s\\dv = \sqrt{(84.84692829)^2+(-23.2440044)^2} = 87.97320604m/s$

Finally, substitute into the equation

$J = m*dv\\J = 0.140kg * 87.97320604m/s\\J = 12.31624885kg*m/s\\J = 12.32 kg*m/s$

J = 12.32kg*m/s

8 0

3 years ago

An object at rest does not _____ and an object in motion does not _____, unless an _____ force acts upon it

mel-nik [20]

Answer:

An object at rest does not move and an object in motion does not change its velocity, unless an external force acts upon it

Explanation:

This statement is also known as Newton's first law, or law of inertia.

It states that the state of motion of an object can be changed only if there is an external force (different from zero) acting on it: therefore

- If an object is at rest, it will remain at rest if there is no force acting on it

- If an object is moving, it will continue moving at constant velocity if there is no force acting on it

This phenomenon can be also understood by looking at Newton's second law:

F = ma

where

F is the net force on an object

m is the mass

a is the acceleration

If the net force is zero, F = 0, the acceleration of the object is also zero, a = 0: therefore, the velocity of the object does not change, and it will continue moving at the same velocity (which can be zero, if the object was at rest).

5 0

3 years ago

What 3 things can an object with unbalanced forces do?

Keith_Richards [23]

Forces are considered balanced when all of the combined forces lead to no change in the motion of the object. For example, when a book is sitting on a table, the force of gravity is pushing downward and the normal force is pushing upward with exactly the same amount of force. Since they are equal and opposite forces, the book does not move.

Unbalanced forces exist when there are unequal forces acting upon the object, which leads to a change in the state of motion. Unbalanced forces can lead to a change in direction, a change in speed, or both a change in direction and in speed.

3 0

3 years ago

A 1000-kg car is moving at 40.0 km/hr when the driver slams on the brakes and skids to a stop (with locked brakes) over a distan

liq [111]

Answer:

skid distance = 180 m

Explanation:

given,

mass of the car = 1000 Kg

speed of the car = 40 Km/hr

distance to stop = 20 m

if speed is now = 120 Km/he

distance to stop = ?

from given question we can state that,

Work done by the friction is equal to the change in kinetic energy of the car.

$W= \dfrac{1}{2}mv^2$ ............(1)

And we also know that work is directly proportional to displacement

W = F × x...........................(2)

from the equation (1) and (2)

x ∝ v²

now,

here velocity is increased from 40 km/h to 120 km/h means velocity is increase 3 times

so displacement will be equal to 3² or 9 times

hence, skid distance will be equal to 9 x 20 = 180 m

skid distance = 180 m

8 0

3 years ago

An electron, moving toward the west, enters a uniform magnetic field. Because of this field the electron curves upward. The dire

Marysya12 [62]

Answer:

<em>The magnetic field's direction is towards the north</em>

Explanation:

The force on a positive charge in a uniform magnetic field is represented by the right hand rule. To determine the direction of the force, place your right hand with your palm up, and your thumb at 90° to the other fingers. If the fingers represent the magnetic field, and the thumb the direction of the positive charge, then the palm will push up in the direction of the force. But a negative charge like an electron pushes in exactly the opposite direction. So if you follow this rule, you will find that the magnetic field points towards the north.

4 0

4 years ago