Mechanics | Relativity Answers

Fc=mv/r
Fc is centripetal force, m is mass, v is speed and r is radius


6. What will happen to the size of the centripetal force if the mass (m) is doubled?


1)No change
2)The centripetal force doubles
3)The centripetal force increases by a factor of 4
4)The centripetal force is halved

When swinging an object on a string, in which direction is the only force acting (excluding gravity)?


1)Inward from the object to your hand
2)Outward away from your hand
3)In the direction that the ball is currently moving
4)Opposite to the direction that the object is currently moving in

Derive the Newtonian addition of velocities formula
vCA = vCB + vBA
for the case shown below where the 3 objects (A, B, and C) do not pass
through the same event. Note that, without loss of generality, we may
take the worldlines of A and B to intersect at t = 0.

Suppose that your car is parked in front of a house. You get in, start
the engine, and drive away. You step on the gas until the speedometer
increases to 30mph, then you hold that reading constant.
Draw two spacetime diagrams, each showing both the house and the car.
Draw one in your own frame of reference, and draw the other in the house’s
frame of reference. Be sure to label both diagrams with an appropriate scale

A race car starting from rest accelerates uniformly at a rate of 4.90 meters per second2. What is the car’s speed after it has traveled 200. meters?

A cat chases a mouse across a 1.3 m high
table. The mouse steps out of the way, and
the cat slides off the table and strikes the floor
2.1 m from the edge of the table.
The acceleration of gravity is 9.81 m/s
2. What was the cat’s speed when it slid off
the table?
Answer in units of m/s. Don't round answer.

Given: The battleship and enemy ships A
and B lie along a straight line. Neglect air
friction.
A battleship simultaneously fires two shells
at these two enemy ships.from a cliff 33.8 m high. At the level of the
sea, a rock sticks out a horizontal distance of
8.29 m.
The acceleration of gravity is 9.8 m/s2. With what minimum horizontal velocity
must the cliff divers leave the top of the cliff if
they are to miss the rock?
Answer in units of m/s.

The radius of the moon is one fourth and its mass is one eight first that of the earth, if the acceleration due to gravity on the surface of the earth is 9.8, what is the value on the moon surface.

A train starts from a rest from a station and start with uniform acceleration 0.5m/s^2 for 20 seconds. It travels with uniform velocity for 30s. The break are then applied so that a uniform retardation is obtained and the train comes to rest in a further 10 seconds. Sketch the velocity time graphy of this motion. Using your graph calculate the total distance traveled by the train and the total distance traveled using the trapezium method.

The Goodyear blimp flies at a cruising speed of 16 meters per second. The blimp requires 500 meters to go from being parked to being at cruising speed. What is the acceleration of the blimp?