Mechanics | Relativity Answers

In an 88 s interval, 588 hailstones strike a
glass window of area 0.624 m2
at an angle 20◦
to the window surface. Each hailstone has a
mass of 6 g and speed of 12.1 m/s.
If the collisions are elastic, find the average
force on the window.
Answer in units of N
Don't round answer.

Suppose Ichiro threw a rock upward with an initial velocity of 8.0 m/s. Determine the velocity and displacement of the rock at 4 s.

The equation of a parabola is y = ax2 + bx + c, where a, b and c are constants. The
x- and y-coordinates of a projectile launched from the origin as a function of time are
given by x = v0xt and y = v0yt − 1gt2, where v0x and v0y are the components of the 2
initial velocity.
(a) Eliminate t from these two equations and show that the path of a projectile is a
parabola and has the form y = ax2 + bx.
(b) What are the values of a, b and c for the projectile?

On a spacecraft, two engines are turned on for 482 s at a moment when the velocity of the craft has x and y components of v0x = 3460 m/s and v0y = 2670 m/s. While the engines are firing the craft undergoes a displacement that has components of x = 2.11×106 m and y = 3.07×106 m. Find the x and y components of the craft’s acceleration.

A 62.7 kg skier rides a 916.6 m long lift to the top of a mountain. The lift makes an angle of 28.3o with the horizontal. How fast will she be traveling when she reaches the bottom of the mountain?

A 83.1 kg skier rides a 1376.8 m long lift to the top of a mountain. The lift makes an angle of 23.9o with the horizontal. How much potential energy does she have at the top of the mountain?

A block with an initial velocity of 8.9 m/s slides across a rough surface until it eventually comes to rest. If the coefficient of friction is equal to 0.83, then how far will the block travel?

A projectile of mass 0.5 kg is shot straight up with an initial speed of 18.8 m/s. How much energy is lost from the system if it reaches a max height of 15.9048 meters?

A 67.9 kg skier is at rest at the top of a 298 m high run. The slope is inclined at a 15.7º angle relative to horizontal. Assuming that there is no friction between the skis and the snow, how fast is the skier traveling when he/she is halfway down the slope?