Suppose that the dipole moment associated with an iron atom of an iron bar is 2.9 × 10-23 j/t. assume that all the atoms in the bar, which is 6.5 cm long and has a cross-sectional area of 1.0 cm2, have their dipole moments aligned. (a) what is the dipole moment of the bar? (b) what torque must be exerted to hold this magnet perpendicular to an external field of 1.7 t? (the density of iron is 7.9 g/cm3 and its molar mass is 55.9 g/mol.)

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?

An object with a mass of 1.5 kg changes its velocity from + 15 m/s to +22 m/s during a time interval of 3.5 seconds. what impulse was delivered to the objects?

Aspring that is stretched 2.6 cm stores a potential energy of 0.053 j. what is the spring constant of this spring?