Answer:
-39.2m/s
Explanation:
Using the equation of motion;
v = u + at
Since the ball is thrown upward, the acceleration due to gravity acting on it will be negative, hence a = -g
v = u - gt
Since g = 9.8m/s²
t = 4.0s
u = 0m/s
v = 0 + (-9.8)(4)
v = 0 + (-9.8)(4)
v = -39.2m/s
Hence the speed of the ball before release is -39.2m/s
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.
The answer is wind forces and Earth’s rotation
A red apple absorbs all colors of visible light except red, so red light
is the only light left to bounce off of the apple toward our eyes.
(This is a big part of the reason that we call it a "red" apple.)
Here's how the various items on the list make out when they hit the apple:
<span>Red . . . . . reflected
Orange . . absorbed
Yellow . . . </span><span><span>absorbed
</span>Green . </span><span><span>. . absorbed
</span>Blue . . </span><span><span>. . absorbed
</span>Violet .</span><span> . . absorbed</span>
<span>Black . . . no light; not a color
White . . . has all colors in it</span>
meter, millimeters, kilometers. liters. kilograms. centimeters etc... look up the rest
