Answer:
2592 km/h
Explanation:
Given that a bullet is shot from a rifle with a velocity of 720 m/s. What is the velocity of the bullet in km/h.
The velocity = 720 m/s
Solution
To convert metres per second to kilometer per hour, you will multiply by 3600 and divide by 1000
720 × 3600/1000
720 × 3.6
72 × 36
2592 km/h
Therefore, the velocity of the bullet in kilometer per hour is 2592 km/h
A) For upward projection.
v = u -gt
but v = 0, thus u = gt,
t = u/g, t= 7.83/9.81, t = 0.798 sec
Therefore, distance, s
S = ut -1/2gt²
= 7.83(0.798) - 1/2(9.81)(0.798²)
= 6.248 - 3.124
= 3.124 m
Total Height is 10.3 + 3.124 = 13.424 m
For the case of free fall
s= ut + 1/2 gt² but u =0
s = 1/2 gt²
t² = (2 × 13.424)/9.81
t² = 2.7368
t = 1.654 s
Therefore, the time the stone remains in air will be 1.654 + 0.798
= 2.452 seconds
b) Speed of the impact on the ground
v= u + gt but, u = 0
thus v = gt
therefore, v = 9.81 × 1.653
= 16.216 m/s
As an object accelerates i.e., change it's velocity(either direction or speed), the position of the object depends on two factor; If the acceleration was direction based then it might have a zero displacement for eg: if it travels in circle. or it might have a net displacement if it travels in a straight line, quantitatively
where,
s = displacement
u = initial velocity
v = final velocity
a = acceleration
t = time
Now, for the hypothesis;
There is no direct relationship between fan speed and acceleration but anyways generally speaking if we do have a relationship that with more fan speed we have a larger displacement of air i.e., a more force i.e., greater acceleration
Thus, it can be said, well not exactly scientific, that with a greater fan speed there will be greater acceleration. if fan speed is increased then acceleration will be more.
:)
The order for the scientific method is
1. Ask a question
2. Form a hypothesis as an if, then statement (If the liquid is blue, then it must be water)
3. Conduct an experiment
4. Collect the observations
5. Analyze the data
6. Draw a conclusion using while restarting your hypothesis