Mechanics | Relativity Answers

A flashlight is held at the edge of a swimming pool at a height h = 2.5 m such that its beam makes an angle of θ = 38 degrees with respect to the water's surface. The pool is d = 3.75 m deep and the index of refraction for air and water are n1 = 1 and n2 = 1.33, respectively.

What is the horizontal distance, D, from the edge of the pool to the point on the bottom of the pool where the light strikes? Write your answer in m.

A candle (ho = 0.22 m) is placed to the left of a diverging lens (f = -0.067 m). The candle is do = 0.36 m to the left of the lens.
Numerically, what is the image distance, di in meters?
Is this real or virtual?
Numerically, what is the image height, hi?

Suppose a 200-mm focal length telephoto lens is being used to photograph mountains 12.5 km away.
What is image distance, in meters, for this lens?
What is the image height, in centimeters, of a 950-m high cliff on one of the mountains?

A person on a bicycle is moving East at 15 m/s on a horizontal road. The total mass of the person plus the bicycle is 9.0 x 101 kg. The person stops pedaling and comes to rest in 12 s. Calculate the average force causing the bicycle to slow down.

I need a free body diagram for the following question

A 58-kg ice skater moves across the ice at a constant speed of 2.0 m/s. She is caught by her 74-kg partner, and then the pair continues to glide together. He is at rest when he catches her, and immediately afterward they both coast.A skater follows the girl at a constant speed of 1.0 m/s. What is the magnitude of the girl's change in momentum in the reference frame of the skater?

The inertia of an object is m measured when the object is at rest in the Earth reference frame. According to Galilean relativity, what is its inertia measured by an observer moving past the object with a constant velocity v⃗ in the positive x direction?
Express your answer in terms of some or all of the variables m and v⃗ . What is the object's momentum according to this observer?

Two identical cars approach each other head-on while traveling at the same speed v. Suppose the same cars are traveling in the same direction at the same speed v. Now what does an observer in the Earth reference frame measure for the speed of the zero-momentum reference frame?

A 50-kg meteorite moving at 1000 m/s strikes Earth. Assume the velocity is along the line joining Earth's center of mass and the meteor's center of mass. Calculate the amount of kinetic energy converted to internal energy measured from the Earth reference frame. What is the gain in Earth's kinetic energy?

A train starting at station A moves along a straight line and stops at station B; distance x of the train from the starting point varies with time t as x= 3/4t^2- t^3/4
Find distance between station A and station B
i) 1unit ii)2 units iii) 1/2 unit
Find maximum velocity of the train.
i)3/4 unit ii)3/2 unit iii)1/4 unit

please show all the steps along with explanation and reply asap