Use energy conservation to calculate the speed!
Total kinetic energy before collision = total kinetic energy after the collision.
Answer:
Newton's first law of motion states that an object at rest will remain at rest and an object in motion will remain in motion unless it is acted on by an unbalanced force. Using unbalanced forces to control the motion of a skateboard demonstrates Newton's first law of motion.
Hope it helps
83 km/h * 2.5 hours (3:30 - 1:00) = 207.5 km
207.5 km - 15 km = 192.5 km
Rock is completely immersed in hot water. By the second law of thermodynamics, thermal energy or heat is transferred from substance with higher temperature to substance with lower temperature until they come to thermal equilibrium i.e. both at same temperature.
It is given here that rock is at 20°C which is at lower temperature than water at 80°C. ∴Heat or thermal energy flows from water to rock. So, right choice is-
A. The water gives the rock thermal energy and gets no thermal energy in return.
