Elastic Forces
Work
Power
Advanced Problems
100

What spring is easier to stretch? A spring with a large k value or a spring with a small k value?

What is a spring with a small k value

100

What type of force is needed to do work

What is a force that is parallel

                   or

What is a force that has displacement

100

Besides using work, what is another way to solve for power?

What is using energy.

100

What type of energy is seen in springs and elastics?

What is Spring Potential Energy

200

What is the force needed to pull an elastic with a spring constant of 20 N/m a distance of .25m?

What is 5N

200

A man pushes a box 10m with a force of 10N. How much work does the man do on the box?

What is 100J.

200

If an elastic does 15 joules of work for 4 seconds. How much power is produced?

What is 3.75W

200

4380J of work is produced pushing a 285kg crate at a rate of 3 m/s2. How far was the crate pushed? (Neglect friction)

What is 5.1m.

300

With a weight of 25 kg, a spring stretches 6 cm, what is the spring constant?

What is 4087.5 (ish)

300

A student produces 15 J of work to push the pencil 2 meters.  How much force did they use?

What is 7.5 N. 

300

If an elevator motor uses 534 W of power in 5s how much work is produced?

What is 2670 J. 

300

When the weight hung on a spring is increased by 60 N, the new stretch is 15 cm more. If the original stretch is 5 cm, what is the original weight?

What is 20N

400

How far is an elastic (with a spring constant of 454N/m) stretched when a 30kg mass is added to it?

What is 0.65m (ish)

400

How much work is done by pushing a 78 kg child on a swing 2m. 

What is 1530J. 

400

A chemical reaction creates 300J of energy and lasts for 15 seconds. How much power did the reaction make?

What is 20W. 

400

A horse pulls a 275kg cart up a 31 meter hill that is at an angle of 150 how much power is produced by the horse if the horse makes it up the hill in 36 seconds? 

What is 2,244 W.

500

A spring stretches 5 cm when a load of 20 N is hung on it. If instead, we put a load of 30 N, how much will the spring stretch?

What is .075m (or 7.5 cm).

500

Instead of lifting a box straight up, you push it up a ramp that is 4.0m long and at a 22° angle. If you push with a force of 37N, how much work do you do on the box? (Note: the ramp is frictionless) 

What is 137 J. 

500

A car engine creates a force of 200N. If a car drives 35 meters how long does the car have to drive to create 833W of power?

What is 8.4 sec. 

500

In just 0.40 seconds, you compress a spring (spring constant 3000), which is initially at equilibrium length, by 8.0cm. What is your average power output? (6 points)

What is 48 Watts. 

M
e
n
u