Mechanics | Relativity Answers

A rock in a sling is swung around in a circle.
How would the centripetal force change if the rock was 8 times lighter??

How would the centripetal force change if the rock was swung 7 times faster?


How would the centripetal force change if the sling was 6 times longer?

A BMW of mass 1500kg drives around a curve of radius 36m.

If the driver keeps a constant speed of 18m/s, what is the force acting on the car?


If the maximum friction the tires can supply to the road is 15660N, what is the maximum velocity the car can take this curve at?


If the driver wants to take a curve at 22.5m/s, what is the minimum radius of the curve so that the driver does not lose traction?
(hint: use the tires maximum traction force from part II)

Which way is the force pushing the car?

From the equation F = mv2/r, the tension in a 2 m length of string that whirls a 3 kg mass at 1 m/s in a horizontal circle is calculated to be 1.50 N. Calculate the tension for the following cases.
(a) twice the mass
(b) twice the speed
(c) twice the length of string (radial distance)
(d) twice mass, twice speed, and twice distance all at the same time

For one dimensional elastic collision, two particles have the same mass. A moving particle collides with another particle at rest. Is it possible for them to have equal speed after collision?

What force is required to accelerate a 0.50 kg cart on a frictionless track at 3.0 m/s2?

An indestructible bullet 2.00 cm long is fired straight
through a board that is 10.0 cm thick. The bullet strikes
the board with a speed of 420 m/s and emerges with a
speed of 280 m/s. (a) What is the average acceleration
of the bullet as it passes through the board? (b) What is
the total time that the bullet is in contact with the
board? (c) What thickness of board (calculated to
0.1 cm) would it take to stop the bullet, assuming
the bullet’s acceleration through all parts of the board
is the same?

Ball is kicked at 20 degree angle of a 40.0 m high cliff into a pool of water. If the player hears the sound of the splash 3.0 seconds later, what was the initial speed given to the ball? Assume the speed of sound in air to be a constant 343 m/s

an arrow is thrown in air its time of flight is 5s &the range is 200m Determine the vertical component of the velocity of projection,horizontal component,max.height and angle made with the horizontal.

If the moon were twice as massive, would the attractive force of Earth on the moon be twice as large?
What about the attractive force of the moon on Earth?

By what factor would your weight change if Earth's diameter were tripled and its mass were quintupled?