A child does 390 J of work while pulling a box from the ground up to his tree house with a rope. The tree house is 4.7 m above the ground. What is the mass of the box?

2select the correct answer. javed suffers from a severe food allergy. which device should javed always carry? a. inhaler b. epi pen c. nebulizer d. insulin pen

In a region of space, a magnetic field points in the +x-direction (toward the right). its magnitude varies with position according to the formula bx=b0+bx, where b0 and b are positive constants, for x≥0. a flat coil of area a moves with uniform speed v from right to left with the plane of its area always perpendicular to this field. part a what is the emf induced in this coil while it is to the right of the origin?

If the contraction of the left ventricle lasts 250 ms and the speed of blood flow in the aorta (the large artery leaving the heart) is 0.76 m/s at the end of the contraction, what is the average acceleration of a red blood cell as it leaves the heart?