# Search results

1. ### Power of the sun

Homework Statement I'm carrying out a lab to investigate the power of the sun. I'm supposed to compare the light intensity of a 100W light bulb with the light intensity from the sun, by comparing the radiating heat on my cheeks (one cheek pointing to the sun, the other to the bulb). I found...
2. ### Magnetic force of a proton

Homework Statement A proton with the speed 3.7*10^6 m/s is moving in a magnetic field, parallel to the field. The magnetic B-force is 0.45T. a)Draw a figure that shows the proton in the magnetic field. Indicate the direction of the proton's velocity, the direction of the magnetic field and...
3. ### Magnetic field strength between two wires homework

Homework Statement Two straight parallel wires are placed vertically on a wall. The distance between the wires is 12 cm and the current through each one is 7.5A. In the left wire the current is directed upwards and in the right one the current points downwards. Determine the magnetic field...
4. ### Coulomb's law

Homework Statement Two small charges q1 = +2.65 nC and q2=-4.75nC are at a certain distance from each other. Q1 is affected by a force of 55μN from q2. a) how large is the force on q2? Draw a figure that shows the electric forces that work on q1 and q2. b) determine the distance between the...
5. ### Forces on a painting

Homework Statement This question comes from a lab that we did a while ago: Hang a painting on a nail by a thread. The weight of the painting was 0.4 kg. a) Calculate the force in the nail that holds up the painting. b) Calculate the forces that work on the thread holding the painting in...
6. ### Bouncing balls

Homework Statement A ball is dropped from a height of 1.75m. It bounces on the floor and reaches a maximum height of 1.35m above the floor. The ball's weight is 98.5g. a) What is the ball's velocity just before and just after the bounce? b) How large is the impulse that the ball gets in the...
7. ### Colliding car

Hello, I've tried solving the following question: A car collides with a tree with a velocity of 75km/h. The car was compressed 1.1m after the collission and the car's mass is 1100kg (including the driver), and the driver's mass is 71kg. a) What is the kinetic energy just before the...
8. ### Friction constant

Hey, i'm having trouble finding the friction constant in the following question: Lisa is sitting on a carousel 0.55m from the centre. The carousel rotates at 15laps/min and Lisa weighs 33kg. a) what is Lisa's velocity? b) Lisa moves away from her spot so that she is rotating 1.2m from the...