small block of mass 200 g is kept at the top of a frictionless incline which is 10 m long and 3.2 m high. How much work was required a. to lift the block from the ground nd put it at the top b. to side the block up the incline? What will be the speed of the block when it reaches the ground if, c. it falls off the incline and drops vertically on the ground d. it slides down the incline? Take `g=10 m/s^2`.

Answer

A, B, C, D

Explanation

`m=200`
`=0.2 kg, S=10m`
`h=3.2m,g=10m/sec^2`
a. work done `W=mgh=0.2xx10xx3.2`
b. Work done to slide the block up the incline`
`W=(mgsintheta)S`
`=(0.2)xx10xx(3.2/10)xx10`
`=6.4J`
c Let the velocity be v when falls on the ground vertically
`1/2 mv^2-0=6.4J`
`rarr v=8m/sec`
d. Let v be the velocity when reached the ground by sliding
`1/2mv^2-0=6.4j`
`v=8m/sec`