Answer:
79.20 joule
Explanation:
1.
A 0.10kg stone is thrown from the edge of an ocean cliff with an initial speed of 21m/s. When it strikes the water below, it is traveling at 45m/s. What is the change in kinetic energy of the stone?
ΔEk = m/2*(V2^2-V1^2) = 0.05*(45^2-21^2) = 79.20 joule
Answer:
Power, P = 600 watts
Explanation:
It is given that,
Mass of sprinter, m = 54 kg
Speed, v = 10 m/s
Time taken, t = 3 s
We need to find the average power generated. The work done divided by time taken is called power generated by the sprinter i.e.
Work done is equal to the change in kinetic energy of the sprinter.
P = 900 watts
So, the average power generated by the sprinter is 900 watts. Hence, this is the required solution.
Answer:
0.25
Explanation:
Magnification = image distance/object distance
mag = v/u.................. Equation 1
Given: f = -10 cm ( diverging lens) u = 30 cm.
Where can calculate for the value of v using
1/f = 1/u+1/v
make v the subject of the equation
v = fv/(u-f)..................... Equation 2
Substitute into equation 2
v = -30(10)/(30+10)
v = -300/40
v = -7.5 cm.
substituting into equation 1,
mag = 7.5/30
mag = 0.25
hence the magnification of the wretch = 0.25
