Explanation:
1) 1 : to Prevent a burning we use tongs
2:it can burn our skin hoa it's help
2) 1: because pulley helps in water draw from a well
3) 1: second class lever has mechanical advantage more than one as load is in between fulcrum an effort making the effort arm longer than the load arm
Answer:
Because the log is hollow or is less dense
Explanation:
If a log has little density, it will float. While sand is dense and completely solid, so it will sink.
Answer:
Work done, W = 1.44 kJ
Explanation:
Given that,
Mass of boy, m = 74 kg
Initial speed of boy, u = 1.6 m/s
The boy then drops through a height of 1.56 m
Final speed of boy, v = 8.5 m/s
To find,
Non-conservative work was done on the boy.
Solution,
The work done by the non conservative forces is equal to the sum of total change in kinetic energy and total change in potential energy.



W = 1447.21 Joules
or
W = 1.44 kJ
Therefore, the non conservative work done on the boy is 1.44 kJ.
D) How fast you are moving