Answer:
The football leaves with the velocity, u = 15.68 m/s
Explanation:
Given data,
The football bounces back up off the ground and is airborne for, t = 3.2 s
Let the football bounces back up off the ground in the vertical direction
The formula for time of flight is given by,
t = 2u /g
∴ u = gt / 2
Substituting the values,
u = 9.8 x 3.2 / 2
u = 15.68 m/s
Hence, the football leaves with the velocity, u = 15.68 m/s
Explanation:
it has no energy when considered with respect to earth ,as it has neither height (i e potential energy) nor velocity (i.e kinetic energy).
Answer:
A, B and D
2. A
Explanation:
1.Which of the following statements about light waves is true? check all correct answers
A.They come from sources across space reason is that a light can travels form its source and its moves across the space
B.They travel in a straight line from their source reason is that the type of light that undergo these is called parallel ray of light
C.They can travel through any type of material reason not all materials light can penetrate through e.g wall
D.They can be reflected by some types of material reason is that some materals reflect light rays e.g polished mirror
We will have the following:
First, we remember that velocity is the change of position with respect to time and this can be seen as the derivative of the position; and that the acceleration is the change of velocity with respect to time and this can be seen as the derivative of the velocity or the second derivative of the position; so:
Then velocity will be:
And finally the acceleration will be:
And thus, when we examine the problem at t = 250s we will have that the acceleration will be 8 units of distance / s^2; this due to the fact that the second derivative is a constant.
Answer:
he can use the laser to point to specific information on the slides.
he can use the laser to point to specific information on the slides.Explanation: