Answer:
option (E) is correct.
Explanation:
Work done is defined as the product of force and the distance in the direction of force.
force, f = 100 N
Coefficient of friction, = 0.25
distance = 15 m
So, net force F = f - friction force
F = 100 - 0.25 x m g
Work = (100 - 0.25 mg) x d cosθ
For minimum work, the angle should be maximum.
So, the value of θ is 76°.
thus, option (E) is correct.
Any process in which a mixture of materials separates out partially
Answer:
C
Explanation:
First find the electrical wattage
W = I^2 * R
R = 12 ohms
I = 2 amps
Wattage = 2^2 * 12
Wattage = 4* 12
Wattage = 48 watts.
Now you need to use the power formula
Work = Power * Time
Work = ?
Power = 48 watts
Time = 3 minutes = 3 * 60 = 180 seconds.
Work = 48 * 180
Work = 8640 J
That's C
Answer: The velocity of the ball is 30.0 m/s
This can be calculated by using the value of acceleration as 10.0 m/s2 in free fall and the given time of 3.0 seconds. To get the
velocity, one will have to multiply the acceleration with the given time and the
quotient would result to 30.0 m/s. Mostly all object regardless of their mass,
fall to earth with the same acceleration in the absence of air resistance and as
the child drops the ball from a window, it gains speed as it falls.
