Answer:
C
Explanation:
If a pulley system has an efficiency of 74.2%, then only that fraction of the work performed will be useful. 74.2%=0.742. 0.742*200 is about 148J. Hope this helps!
Answer:
Q = 12540 J
Explanation:
It is given that,
Mass of water, m = 50 mL = 50 g
It is heated from 0 degrees Celsius to 60 degrees Celsius.
We need to find the energy required to heat the water. The formula use to find it as follows :

Where c is the specific heat of water, c = 4.18 J/g°C
Put all the values,

So, 12540 J of energy is used to heat the water.
Answer:
7. Your answer is correct dear, just add the unit
8. answer is 1.17m/s²
Explanation:
queation 7.
m = 3kg, F = 9N, a ?
F = ma
a = F/m = 9/3 = 3m/s²
Use the same approach for question 8
Answer:
Twice
Step-by-Step Explanation:
Time between 7:00 PM and 1:00 AM: 6 hours
Distance: 4818km
Since the distance is 4818km, and the time is 6 hours, you divide 4818 by 6.
803.0000015999 km/h.
The average speed is 803 km/h
Which considering the ideal case scenario if the plane starts at 0 reaches the speed of 803 and the end reduces its speed from 803 to 0. This means we have come across the value of 800 at least twice. Hence, the plane was travelling at a speed of 800 km/h at least 2 times.
Answer:
11300 kgm3
Hope this helps