A force is applied to a block on a frictionless inclined surface as shown in the diagram. What magnitude force is necessary to keep the block from sliding down the incline? The mass of the block is 69.7 kg and the angle of incline is 45.2 degrees. The magnitude of the force is _?

Janelle made a hypothesis bout the uneven temperatures inside her house during winter. she believes that 50% of the ducts are blocked and she plans to investigate. if she wants to prove her hypothesis using scientific processes what should she do next?

The force will determine the acceleration.

Alead ball is dropped into a lake from a diving board 5m above the water . it hits the water with a certain velocity and then sink with constant velocity in bottom . it reaches the bottom 5 second after it is dropped if g= 10m/s2 . find depth of the lake and average velocity of the ball ?