Mechanics | Relativity Answers

1. You’re riding a unicorn at 25 m/s and come to a uniform stop at a red light 20 m away. What’s your acceleration?

What amount of energy is released if two mercury droplets of radii 0.1 & 0.2cm collapse into one single drop. The surface tension of mercury is 500x10^-3 Nm^-1?

A jet is travelling at a speed of 1200 km/h and drops cargo from a height of 25 km above the ground. Calculate the time it takes for the cargo to hit the ground and the range it travels

Consider a run away train. The train has a mass of 200,000 kg. The train is traveling at 25 m/s . In an attempt to slow down the the train, the engineer puts another train in the run away train's path. The second train has a mass of 150,000kg. The second train is traveling at 15m/s in the same direction as the run away train. When the trains collide, they stick together. How fast will the train be traveling after the collision ( assume the train are not being powered by engines)

A car and a truck start from rest at the same instant with the car initially at same distance behind the truck. The truck has constant acceleration of 3.4 m/s^2. The car overtakes the truck within the truck has moved a distance of 40.0 m.

a. How far was the car behind the truck initially?
b. How much time does it take the car to overtake the truck?
c. What are their speeds when they are abreast?

An ostrich with a mass of 143 kg is running to
the right with a velocity of 12 m/s.
Find the momentum of the ostrich.
Answer in units of kg · m/s

What velocity must a car with a mass of
1060 kg have in order to have the same mo-
mentum as a 2380 kg pickup truck traveling
at 27 m/s to the east?
Answer in units of m/s

A 0.43 kg football is thrown with a velocity
of 12 m/s to the right. A stationary receiver
catches the ball and brings it to rest in 0.023
s.
What is the force exerted on the receiver?
Answer in units of N

USE conservation of momentum for-
mula. The astronaut will have the same mo-
mentum as the oxygen tank - only in the
reverse direction. ——
A 62.5 kg astronaut is on a space walk when
the tether line to the shuttle breaks. The
astronaut is able to throw a 11.0 kg oxygen
tank in a direction away from the shuttle with
a speed of 11.4 m/s, propelling the astronaut
back to the shuttle.
Assuming that the astronaut starts from
rest, find the final speed of the astronaut after
throwing the tank.
Answer in units of m/s

——since the question states that East is pos-
itive, and the fisherman is moving west, then
when the fisherman jumps into the rowboat,
they will both be moving west. Therefore the
velocity should be NEGATIVE.——
Note: Take East as the positive direction.
A(n) 80 kg fisherman jumps from a dock into a 129 kg rowboat at rest on theWest side
of the dock.
If the velocity of the fisherman is 4.7 m/s
to the West as he leaves the dock, what is the
final velocity of the fisherman and the boat?
Answer in units of m/s