1. There are (three) slides in the park. 对划线部分提问.

这道流体力学题的正确答案是多少
A 12-kg cube slides down an inclided plane making an angle of 30°with the horizontal.A fluid film 0.1mm thick separates solid and surface.The fluid viscosity is 0.04 newton-seconds per square meter.Assuming the velocity distribution in the film is linear,find the terminal velocity of the block.The area of the cube in contact with the film is 0.25 square meters.
A 12-kg cube slides down an inclined plane making an angle of 30°with the horizontal.A fluid film 0.1mm thick separates solid and surface.The fluid viscosity is 0.04N.s/m2.Assuming the velocity distribution in the film is linear,find the terminal velocity of the block.The area of the cube in contact with the film is 0.25 m2.

I've also brought a few slides of some large mineral samples.这里的slides是什么意思

slides are soetimes called _film.
A whistle b vigorous c robot d transparent

An ashtray slides across a table with a speed of 0.6m/s and falls off the edge.If it takes 0.4s to reach the floor,how far from the edge of the table does it land?

A car drives off a vertical cliff at a speed of 29m/s (60mph).If it takes 4s for it to hit the ground,how far from the base of the cliff does it land?
A tennis ball is hit with a vertical speed of 10m/s and a horizontal speed of 20m/s.How long will the ball remain in the air?How far will it travel horizontally during this time?
If a baseball is hit with a vertical speed of 20m/s and a horizontal speed of 12m/s ,how long will the ball remain in the air?How far will it go?

一道英文物理题求解（有点难 ）

A block starts from rest and slides without friction along the surface of a hemisphere of radius R= 4.90 m. As the block slides, eventually it loses contact with the hemisphere.

1.Select all the statements that are correct; e.g., if A and D are correct and the rest are incorrect, enter AD. If none are correct, enter N.

At the moment the block leaves the surface, its acceleration is parallel to its velocity.

Before the block leaves the surface of the hemisphere, the only forces that act on it are gravity and the normal force.

While the block slides along the surface of the hemisphere, its acceleration only has a component perpendicular to its velocity.

As the block slides downward, the magnitude of the normal force on the block increases.

The magnitude of the change in potential energy of the block as it moves is equal to the magnitude of the change in its kinetic energy.

2.When the block is at an angle θ=17.8°, what percentage of the block's weight is the component perpendicular to the surface of the hemisphere? Don't enter units.

3.When the block is at an angle θ=15.0°, what is the speed of the block?

4.What is the speed of the block when it loses contact with the hemisphere?

英语翻译

A 0.48 kg block slides along a small track with elevated ends and a flat central part.The flat part has a length L = 1.18 m.The curved portions of the track are frictionless,but for the flat part the coefficient of kinetic friction is 0.101.The block is released from rest from a height h = 84 cm on the left curved portion of the track.Calculate the maximum height reached by the block on the right curved portion of the track.



Which of the following statements are true?E.g.,if the first is true and the rest false,enter TFFFF.



Two balls with different masses reach the same height when shot into the air from the ground.If there is no air drag,both balls must have left the ground with the same speed.

Two objects,with different masses,have a gravitational potential energy of 100 J each; they are released from rest and fall to the ground.Both objects were released from the same height.

The formula W = F·d·cosθ can be used only if the force is constant over the distance d.

Consider a train that pulls a wagon.By Newton's third law,the wagon pulls on the train with an equal opposite force,therefore the work done by the train must be zero.

If a force acts downwards,it does negative work.

they want to visit the word's water slides
是一个单词的适当形式填空（large)

关于world's largest water slides的问题
world's是名词所有格吗 largest最高级怎么没有定冠词the

答案是slide,slides,swing,swings 这里的slide跟swing为什么不用过去式?
When I was little,my favorite thing o do was to go to the playground and _______ down ________ and _______ on _______.
还有,请翻译这个句子