Number a is a correct one
A. 90km/h = 25 m/s
W=1/2mv^2
=1/2* 650* 25^2
= 203125(J)
b. v’= 90-50= 40km/h
= 100/9 m/s
W=1/2mv^2
=1/2*650*(100/9)^2
= 40123,45679
Gas pressure will also increase then.., if volume is kept constant
Answer: 1608.39 J
Explanation: Given that the
mass M = 42kg
U = 11.5m/s
V = 3.33m/s
how much work did friction do
Work done = Force × distance
Work done = Ma × distance
But acceleration a = V/t
Work done = M × V/t × d
Work done = M × V × d/t
Where d/t = velocity
Therefore,
Work done = M × U × V
Work done = 42 × 11.5 × 3.33
Work done = 1608.39 J
