Answer:
I don't know if it is correct or not.
Answer:
6.65m/s
Explanation:
Using the equation of motion
S = ut + 1/2gt²
S is the height of fall
t is the time
u is the horizontal velocity
g is the acceleration due to gravity
Given
S = 300 + 50
S = 350m
t = 7.8seconds
g = 9.8m/s^2
Get S
S = 7.8u + 1/2(9.8)(7.8)²
S = 7.8u + 298.116
350 = 7.8u + 298.116
7.8u = 350 - 298.116
7.8u = 51.884
u = 51.884/7.8
u = 6.65m/s
Hence the rock's horizontal velocity was 6.65m/s
Been a while since i've done a problem like this so i might be wrong in the "work" aspect
your system starts with 1200J
you add 700J of heat-
add 700 to 1200
1200+700
and your system does 400J of work
since work is being done by the system, the energy is leaving the system hence you subtract
1900-400
the result is then 1500
A) gravity is the attraction of any mass to any other other mass .
D) gravity is a force that exist between any two masses in the universe
both are ok ...
Answer:
Remember the equation:
F = m*a
where F is force, m is mass and a is acceleration.
If we have F constant. and we want that increases, then we can have the case where m decreases.
The mass can decrease in cases like a rocket, where as the fuel of the rocket consumes, the mass of the rocket decreases and the acceleration increases.
b) The cases where a constant force results in a constant acceleration of zero, is when the force is canceled, an example of this is the constant force of the gravity in all the objects. The objects that are in the ground are being affected by this force, but the gravitational force is canceled with the normal force of the ground. Then we have a constant force that does not cause any acceleration.
