[روح لم يمسها عابر]

عندي شيتين فيه 5 اسئله وبمتحن عليها..
فهموني كيف الحل..


Q1:
A car travelling at 20 m/s decelerates at 5 m/s2.
How far will the car travel before stopping?
Answer: 40 m

Q2:
A car starts from rest and accelerates in a straight line at 1.6 m/s2 for 10s.
a. What is its final speed?
b. How far has it travelled in this time?
If the brakes are then applied and it travels a further 20m before stopping
c. What is the deceleration ?
Answer: a. 16 m/s
b. 80 m
c. 6.4 m/s2

Q3 :
A hoist starts at ground level and accelerates as 1.2 m/s2 for 5s.
It then moves with uniform speed for 10s and is finally brought to rest at the top of a building with a deceleration of 2.0 m/s2.
a. Draw the speed time graph of the motion
b. Find the time of deceleration
Answer: b. 3 sec
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Q1 :
Calculate the potential energy, kinetic energy, mechanical energy, velocity, and height of the skater at the various locations.
Answer:
1. 0 J; 1.92 kJ; 1.92 kJ
2. 588 J; 1.33 kJ; 1.92 kJ; 6.66 m/s
3. 1.92 kJ; 0 J; 1.92 kJ; 0 m/s ; 3.27 m



Q2:
Prove principle of energy conservation at the helicopter mass of 5000 grams and moving at 24.24 m/ s been flying at a height of 20 meters above 10 meters above the ground?

Answer: 1470 J