Why do electrical devices have resistance

A book falls off a 3 meter shelf. How fast will the book go?

A 100-n force has a horizontal component of 80 n and a vertical component of 60 n. the force is applied to a box which rests on a level frictionless floor. the cart starts from rest, and moves 2.0 m horizontally along the floor.

All of the following are examples of convection currents, except: A. Warm air rising B. Cold water sinking to the bottom of the lake C. Water flowing through pipes D. Steam from hot soup rising into the air

Tina lifted a box 0.5 m. the box weighed 25 n. how much work did tina do on the box?

A hockey puck is pushed by a stick with a force of 750 newton's. the puck tracked 2.0 meters in 0.30 seconds. how powerful is the push? (ignore frictional effects.) a. 1,500 W b. 5,000 W c. 112 W d. 450 W

Which of the following is not an application of Doppler technology? police speed guns weather radar ultrasound imaging of the liver determining the motion of a star

For a constant voltage, increasing the resistance will cause the current to decrease. true or false

Which of the following is an example of a testable scientific hypothesis? A) Why do plants grow better in the Sun than in the shade? B) Peacocks have prettier tail feathers than pigeons do.

A passenger jet flies from one airport to another 1,273 miles away in 2.2 h. find its average speed.

Wich statement best describe why an island food web could be considered a closed system