Mechanics | Relativity Answers

Physics help (Kinetic Energy)

A bead with mass (1.8x10^-2)kg is moving along a wire in the positive direction of an x axis. Beginning at time=0, when the bead passes through x=0 with speed 12m/s, a constant force acts on the bead, the picture indicates the bead's position at these four times: t0=0 sec., t1=1.0 sec., t2=2.0 sec., t3=3.0 sec., The bead momentarily stops at t=3.0 sec. What's the kinetic energy of the bead as t=10 sec?

Do I use the K=(.5)mv^2 formula
or
the vf^2=vi^2+2ad formula, THEN the K-formula?

Golf ball exploration!
I am doing this project for class, but I am having a little difficulty can you help me solve the problem?
Directions: Explore the relationship between the height of a golf ball before dropping it and its height after one bounce.
*THIS IS WHAT IT WANTS ME TO DO: A golf ball should be dropped from an initial height of 12 inches. (NOTE: I am dropping this BALL on a smooth concrete pavement) Estimate the bounce height of the ball. Then do it again only this time drop it from 24 inches, 36 inches, 48 inches, 60 and 72 inches. Then compute the average bounce heights for each of the drops. Then turn it into an equation. How do I do this?

A 121 kg physics professor has fallen into the Grand Canyon. Luckily, he managed to grab a branch and is now hanging 73 m below the rim. A student (majoring in linguistics and physics) decides to perform a rescue/experiment using a nearby horse. After lowering a rope to her fallen hero and attaching the other end to the horse, the student measures how long it takes for the horse to pull the fallen physicist to the rim of the Grand Canyon. The acceleration of gravity is 9.8 m/s^2.
If the horse’s output power is truly 1 horsepower (746 W), and no energy is lost to friction, how long should the process take?
Answer in units of s

A 1927 kg car has a speed of 10.3 m/s when it hits a tree. The tree doesn’t move and the car comes to rest. Find the change in kinetic energy of the car.
Answer in units of J.

Find the amount of work done by the car as its front is pushed in.
Answer in units of J.

Find the magnitude of the force that pushed the front of the car in by 48 cm .
Answer in units of N

A 34.0 crate is initially moving with a velocity that has magnitude 4.06 in a direction 37.0 west of north.
How much work must be done on the crate to change its velocity to 6.17 in a direction 63.0 south of east?
Express your answer to three significant figures and include the appropriate units.

In the spin cycle of a washing machine, the tub of radius 0.44 m rotates at a constant rate of 705 rev/min. What is the centrifugal forcess acts on clothes having capacity 7 Kg.Answer in units of N.

A 100g stone is thrown straight upwards at 19 m/s from the top of a 75 m building.

(a) What is the Stone's velocity as it hits the ground?
(b) What is the maximum height of the stone?
(c)What is the stone's kinetic energy when the gravitational potential energy is 30% less than when it started?
(d) What is the stone's gravitational potential energy 1.0 s before it touches the ground?

A rain cloud contains 1.73 × 10^7 kg of water
vapor.The acceleration of gravity is 9.8 m/s^2
.
How long would it take for a 4.9 kW pump
to lift the same amount of water to an altitude
of 24000 m?
Answer in units of years

A 2-kg block slides on a frictionless horizontal surface and is connected on one side to a spring (k=40 N/m) as shown in the figure. The other side is connected via a massless rope to a 4-kg block that hangs vertically. The system starts from rest with the spring unextended. What is the maximum extension of the spring? What is the speed of the 4-kg block when the extension is 50 cm?

Robbie is playing pioneer and pumping water from a well with a hand pump. Each pump moves 12.2 kg of water for 10 seconds of pumping. Robbie must supply an average force of 155 N to move the handle of the pump 0.56m each pump. If the pump moves the water a height of 5.6 m, find the efficiency of the pump