Using Newton's second law of motion:
F=ma ; [ F = force (N: kgm/s^2);m= mass (kg); a = acceleration (m/s^2)
Given: Find: Formula: Solve for m:
F: 2500N mass:? F=ma Eq.1 m=F/a Eq. 2
a= 200m/s^2
Solution:
Using Eq.2
m= (2500 kgm/s^2)/ (200m/s^2) = 12.5 kg
Answer:
117.72kW
Explanation:
Given data
Mass m= 50kg
height x = 2m
time taken = 2 minutes= 129 seconds
let us find the work done
WD= force * distance
WD= mgx
WD= 50*9.81*2
WD= 981 Joules
Let us find the power
Power= work * time
Power= 981*120
Power= 117720
Power= 117.72 kW
Hence the power spent is 117.72kW
Answer:
emf induced in the loop, at the instant when 9.0s have passed = 1.576 * 10 ⁻² V.
Direction is counter clockwise.
Explanation:
See attached pictures.
Answer:
1.84 kJ (kilojoules)
Explanation:
A specific heat of 0.46 J/g Cº means that it takes 0.46 Joules of energy to raise the temperature of 1 gram of iron by 1 Cº.
If we want to heat 50 g of iron from 20° C to 100° C, we can make the following calculation:
Heat = (specific heat)*(mass)*(temp change)
Heat = (0.46 J/g Cº)*(50g)*(100° C - 20° C)
[Note how the units cancel to yield just Joules]
Heat = 1840 Joules, or 1.84 kJ
[Note that the number is positive: Energy is added to the system. If we used cold iron to cool 50g of 100° C water, the temperature change would be (Final - Initial) or (20° C - 100° C). The number is -1.84 kJ: the negative means heat was removed from the system (the iron).
Answer: The volume of gas expands because of the decrease in pressure as he tries to exit the water body, therefore he must take necessary precaution.
Explanation:
Using Boyle's law which states that the the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature
ie P1VI=P2V2
A diver absorbs compressed nitrogen gas when he dives into the water body, As he ascends out of the water body having less pressure, the volume of nitrogen gas which he absorbs will tend to expand following Boyle's Law. Therefore a scuba driver should not rises quickly but slowly to the surface or else the expanding nitrogen gas can cause tiny bubbles in his blood and tissue to form together with joints pains and eventually cause decompression sickness needing medical attention.
