Answer:
Explanation:
Work done in lifting the weight once = mgh
= 20 x 9.8 x (1.9+1.7)
= 705.6 J
= 705.6 / 4.2 calorie
= 168 cals
Total energy to be spent = 600 x 10³ cals
No of times weight is required to be lifted
= 600 x 10³ / 168
= 3.57 x 10³ times
Total time to be taken = 2 x 3.57 x 10³
= 7.14 x 10³ s
=119 minutes .
Answer:
150 N
Explanation:
Given that,
- Acceleration (a) = 3 m/s²
- Mass of the bike (m) = 50 kg
We are asked to calculate force required.
F = ma
F = (50 × 3) N
<u>F</u><u> </u><u>=</u><u> </u><u>1</u><u>5</u><u>0</u><u> </u><u>N</u>
Answer:
The heat change of the system is 30 J.
Explanation:
Given;
increase in internal energy of a system, ΔU = 80 J
work done on the system, W = 50 J
The heat change of the system can be calculated from first law of Thermodynamics;
ΔU = Q - W
where;
Q is the heat absorbed by the system
W is the work done by the system (negative when work is done by the system and positive when work is done on the system)
Since work was done on the system the increase internal energy is given as;
ΔU = Q + W
ΔU - W = Q
80 J - 50 J = Q
30 J = Q
Therefore, the heat change of the system is 30 J.
Answer:
D
Explanation:
technically D and C are correct but your teachers probably a moron and doesnt know that sublimation is a thing