Mechanics | Relativity Answers

a visitor to a lighthouse wishes to determine the height of the tower. she ties a spool of thread to a small rock to make a simple pendulm, which she hangs down the center of a spiral staircase of the tower. The period of oscillation is 10.8s. The acceleration of gravity is 9.8 m/s. What is the height? Answer in units of m

1. A spaceship is launched and starts moving directly towards the Moon. At what
distance from the Earth will the pull of the Moon on the spaceship exceed the
pull of the Earth? Ignore the effect of the Sun in this calculation.

What is the frequency of a wave if its wavelength is 3.6 x 10-9 m and its velocity is 3.0 x 108 m/s?

a 100 kg car pullin a 500 kg trailer accelerates at a rate of 2 m/s. if the frictional force on the trailer is 1000N, with what force does the car pull the trailer? with what force does the trailer pull the car?

About how many kilograms of boiled potatoes would you have to eat to supply energy for half an hour of swimming? Assume that your body utilises only 20 per cent of the total energy stored.

a 2000 kg truck rolls down a hill which is 10 m high. the kinetic energy at the bottom is found to be 1.5 x 10^5 J. what is the efficiency of the ramp in converting gravitational potential energy into kinetic energy?

The driver of the compact car in the previous problem suddenly applies the brakes hard for 2.0 s. As a result, an average force of 5.0x10^3 N is exerted on the car to slow it down. The previous problem has a car that weighs 725 kg that is moving at 115 km/h that has a momentum of 2.32x10^4 kgm/s eastward. Also has another car that weighs 2175 kg with a velocity of 38.4 km/h. What is the change in momentum; that is, the magnitude and direction of the impulse, on the car? Complete the "before" and "after" sketches, and determine the momentum and the velocity of the now.

The driver of the compact car in the previous problem suddenly applies the brakes hard for 2.0 s. As a result, an average force of 5.0x10^3 N is exerted on the car to slow it down. The previous problem has a car that weighs 725 kg that is moving at 115 km/h that has a momentum of 2.32x10^4 kgm/s eastward. Also has another car that weighs 2175 kg with a velocity of 38.4 km/h. What is the change in momentum; that is, the magnitude and direction of the impulse, on the car? Complete the "before" and "after" sketches, and determine the momentum and the velocity of the now.

a ball of mass m traveling horizontally with velocity v strikes a wall and rebounds back along its original path with no change in its speed what is the magniture of thee impulse delivered to the ball by the wall

4 students are pulling on the same object in 4 different directions.One student pulls with a force of 5.5N to the west, the second student oulls with a force 8.75N to the north, the third student pulls with a force of 10.15 to the south and the fourth student pulls with a force of 4.0 to the east. IF the objext has a mass of 0.kg find:
A) Fnet x
B)Fnext y
C)Fnet
D) Acceleration