Initial velocity = 0
time = 2.50 s
acceleration = gravity, 9.8 m/s^2
use the equations for linear motion.
s = ut + (1/2)at^2
v = u + at
A. displacement given u, a and t.
s = (0)(2.50) + (1/2)(9.8)(2.50)^2
s = 0 + 4.9(6.25)
s = 30.625 m
three significant figures..
s = 30.6 m
B. final velocity given u, a and t
v = 0 + 9.8(2.50)
v = 24.5 m/s
C. graphs
s vs. t
object starts at zero and displacement increases linearly to (2.5, 30.6) and stops. slope of line is average velocity, s/t
v vs. t
object starts at zero velocity and increases linearly to (2.5, 24.5) and stops. slope of line is acceleration, v/t.
a vs. t
acceleration is gravity, it's constant horizontal line at; y = 9.8. stops at (2.5,9.8)
Answer:
10.6 s
Explanation:
First of all, let's convert both speeds into m/s:
- Cheetah:
- Gazelle:
Taking as reference the position x = 0, the position of the cheetah at time t is
while the position of the gazelle, which starts 68.8 m ahead, is
The cheetah catches the gazelle when the two positions are equal:
and substituting the speeds and solving for t, we find the time at which the cheetah reaches the gazelle:
The controlled variable is the one that you keep constant. The responding variable or variables is what happens as a result of the experiment (i.e. it's the output variable).
According to the conservation of momentum. In this situation, the initial momentum is equal to zero.
Since,
p=mv (Momentum)
The initial velocity of the ball = 0 m/s
The initial velocity of the man = 0 m/s
Therefore,
Total Momentum = 0
Law of Conservation of momentum states that the vector sum of the final momenta must be equal to zero which means they will have the same magnitude but in opposite directions.
<span>When the ball is kicked forward along the surface with a speed 15 m/s.
</span>then the momentum will be:
p = 4 x 15 = 60 kgm/s.
Now, the momentum of the man can be calculated as:
p = 60 kgm/s
mv = 60 kgm/s
As,
mass of the man = 80kg
So,
80 × v = 60 kgm/s
v = 60÷80
v = 0.75 m/s