Air is composed of many gases, while water is composed of a pure substance. Which best compares air and water?

A rocket starting from its launch pad is subjected to a uniform acceleration of 100 meters/second2. Determine the time needed to

balandron [24]

The velocity is the integral of acceleration. If acceleration is 100 m/s^2 then velocity is:

$v= \int\limits^{}_{}100 \, dt=100t$

So to know the velocity at any time, t, we just put t in seconds into this equation. To know at what time we get to a certain velocity, we set this equation equal to that velocity and solve for t:

$100t = 1000 \\ \\ t= \frac{1000}{100} =10s$

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2 years ago

A ball is rolling along at speed v without slipping on a horizontal surface when it comes to a hill that rises at a constant ang

MissTica

Answer:

The ball has an initial linear kinetic energy and initial rotational kinetic energy which can both be converted into gravitational potential energy. Therefore the hill with friction will let the ball reach higher.

Explanation:

The ball has an initial linear kinetic energy and initial rotational kinetic energy which can both be converted into gravitational potential energy. Therefore the hill with friction will let the ball reach higher.

This is because:

If we consider the ball initially at rest on a frictionless surface and a force is exerted through the centre of mass of the ball, it will slide across the surface with no rotation, and thus, there will only be translational motion.

Now, if there is friction and force is again applied to the stationary ball, the frictional force will act in the opposite direction to the force but at the edge of the ball that rests on the ground. This friction generates a torque on the ball which starts the rotation.

Therefore, static friction is infact necessary for a ball to begin rolling.

Now, from the top of the ball, it will move at a speed 2v, while the centre of mass of the ball will move at a speed v and lastly, the bottom edge of the ball will instantaneously be at rest. So as the edge touching the ground is stationary, it experiences no friction.

So friction is necessary for a ball to start rolling but once the rolling condition has been met the ball experiences no friction.

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2 years ago

A 2.03 kg book is placed on a flat desk. Suppose the coefficient of static friction between the book and the desk is 0.602 and t

diamong [38]

Answer:

11.98 N

Explanation:

Normal force = mg = 2.03 * 9.81

coeff of static friction must be overcome for the book to begin moving

.602 = F / (2.03 * 9.81) = 11.98 N

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