How does the density of a water in a tank and the density of a water in a glass can be same density since water's density is 1
and it's formula is mass/volume
since the tank's water is more than as a volume that of the glass and also more than as a mass that of a glass

Amass m = 74 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius r = 18.4 m and finally a flat straight section at the same height as the center of the loop (18.4 m off the ground). since the mass would not make it around the loop if released from the height of the top of the loop (do you know why? ) it must be released above the top of the loop-the-loop height. (assume the mass never leaves the smooth track at any point on its path.) 1. what is the minimum speed the block must have at the top of the loop to make it around the loop-the-loop without leaving the track? 2. what height above the ground must the mass begin to make it around the loop-the-loop? 3. if the mass has just enough speed to make it around the loop without leaving the track, what will its speed be at the bottom of the loop? 4. if the mass has just enough speed to make it around the loop without leaving the track, what is its speed at the final flat level (18.4 m off the ground)? 5. now a spring with spring constant k = 15600 n/m is used on the final flat surface to stop the mass. how far does the spring compress?

Acar going 10 m/s starts accelerating at a rate of 3 m/s2 for 4 seconds calculate the final velocity of the car

Two balls, each with a mass of 0.5 kg, collide on a pool table. is the law of conservation of momentum satisfied in this collision? explain why or why not.