Answer:
2.49 seconds
Explanation:
From the question,
a = (v-u)/t............................ Equation 1
Where a = acceleration, v = final velocity, u = initial velocity, t = time
Make t the subject of the equation
t = (v-u)/a.......................... Equation 2
Given: v = 6.5 m/s, u = 11 m/s, a = -1.81 m/s²
Substitute these values into equation 2
t = (6.5-11)/(-1.81)
t = -4.5/-1.81
t = 2.49 s
Answer:
The correct answer is - 63.61 miles/hour.
Explanation:
Meter and miles both are the measuring units of distance and speed units are meter per second and miles per hour. The numerical relation between these two units are as follows:
1 meter per second = 2.24 miles per hour
The car travels 28.4 m/s so in miles per hour it would be:
So, 28.4 meters per second = 28.4 * 2.24 miles per hour
28.4 meters per second = 63.61 miles per hour.
Thus, the correct answer is - 63.61 miles per hour.
Answer:
Yes it is possible to increase the power with out changing the amount of work.
Explanation:
The power is defined by the amount of power divided by the time. This time is the one needed to do the work. We can understand this issue by analyzing an example with numeric values.
Work = 500 [J]
Time = 5 [s]
Power will be:
![Power=\frac{500}{5} \\Power=100 []watt]\\](https://tex.z-dn.net/?f=Power%3D%5Cfrac%7B500%7D%7B5%7D%20%5C%5CPower%3D100%20%5B%5Dwatt%5D%5C%5C)
Now if we change the time to 2 seconds:
![Power = 500 [J]/2[s]\\Power = 250 [watt]\\](https://tex.z-dn.net/?f=Power%20%3D%20500%20%5BJ%5D%2F2%5Bs%5D%5C%5CPower%20%3D%20250%20%5Bwatt%5D%5C%5C)
As we can see, the power was increased without the need to change the work.
