Calculate the change in temperature of 20 kg of water if 30 kg of aluminum is dropped in the water and the aluminum changes temperature by 20°C (Hint: use the principle of conservation of energy.) °C

The boat's velocity relative to the riverbank can be resolved into two components. the component going north is 2.7 m/s and the component going west is 1.2 m/s.we add these two vectors and then find the magnitude of the resultant to get the speed.the magnitude of the resultant vector from adding can be obtained by the pythagorean theorem.    to two significant figures, the boat's speed relative to the riverbank is 3.0 m/s.

Ive never heard of creep meters

Ray 2 should cross through the focal point on the right side of the lens

Ithink the answer for this is: an electromagnet is a magnet  with a soft metal core.