Recent content by 13physicsdude

thanks you!

Please help -- Efficiency of car engine question... Unit test tomorrow Homework Statement A car's engine is only 12% efficient at converting chemical energy in gasoline into mechanical energy. If it takes 18000 N of force to keep the car moving at a constant speed of 21 m/s, how much chemical...

Homework Statement A roller coaster descends 55m from the top of the first high point to the first low point in the track. The roller coaster converts gravitational potential energy to kinetic energy with an efficiency of 50.0%. What is the velocity of the roller coaster at the bottom of the...

alrighty, thanks everyone! :)

ya never mind ap123 was correct, I changed the units which gave me 5 m/s2= acceleration, which gave me 125 N force per dog for part "A"... I then multiplied by 4 because there's 4 dogs and I got 500N and plugged that into part "B" in replace of 1800N... which gave me the final answer for part...

Is ap123 correct? should I convert it from km/h to m/s?

HELP! Is my answer correct?? Is negative Friction possible?!? Homework Statement A dogsled team has four dogs that pull a person and a sled with a combined mass of 100 kg. A) They start from rest and reach a speed of 45 km/h in 2.5s. What is the average force applied by each dog? B) Suppose...

im asking if my answer is correct... and in the title I'm expressing that the question doesn't seem to make much sense

HELPHow is this possible?!? The hanging mass is lighter then the cart! Homework Statement The cart in Figure 4 has a mass of 2.3 kg and is attached to a 1.7 kg object. Calculate the acceleration of the cart given the following assumptions. A) The force of friction is negligible B) The...

Finding acceleration of box-- given mass of box and magnitude of frict Doing homework and stuck on this question. A student pushes a 10kg box and let's it slide across the floor. The magnitude of the frictional force acting on the box is 40 N. What is the acceleration of the box? Relative...