A car of 15 kg is traveling on a circular track. If the radius of the track is 7.8 m and the period is 8.5 seconds, what's the centripetal force on
the car? (Round to the nearest hundredth)

Aparticle initially moving east with a speed of 20.0 m/s, experiences an acceleration of 3.95 m/s, north for a time of 8.00 s. what was the speed of the particle after this acceleration, in units of m/s? give the answer as a positive number.

What are atoms of the same element with varying number of neutrons

What is the change in internal energy if 20 j of heat is released from a system and the system does 50 j of work on the surroundings? a. -70 j b. 30 j c. -30 j d. 70 j