A given wood has a dimension of 2m length ,50cm width and 10cm thickness if it floats while 25% of its volume is above the water then what would be its mass

Abaseball is thrown a distance of 20 meters. what is its speed if it takes 0.5 seconds to cover the distance

The position of a dragonfly that is flying parallel to the ground is given as a function of time by r⃗ =[2.90m+(0.0900m/s2)t2]i^− (0.0150m/s3)t3j^. a: at what value of t does the velocity vector of the insect make an angle of 34.0 degree clockwise from the x-axis? b: at the time calculated in part (a), what is the magnitude of the acceleration vector of the insect? c : at the time calculated in part (a), what is the direction of the acceleration vector of the insect?

What is the major limitation to the light microscope?