Answer:
a = 3.125 [m/s^2]
Explanation:
In order to solve this problem, we must use the following equation of kinematics. But first, we have to convert the speed of 90 [km/h] to meters per second.
![90\frac{km}{h}*\frac{1000m}{1km}*\frac{1h}{3600s} \\= 25 \frac{m}{s}](https://tex.z-dn.net/?f=90%5Cfrac%7Bkm%7D%7Bh%7D%2A%5Cfrac%7B1000m%7D%7B1km%7D%2A%5Cfrac%7B1h%7D%7B3600s%7D%20%20%20%5C%5C%3D%2025%20%5Cfrac%7Bm%7D%7Bs%7D)
![v_{f} =v_{i} + (a*t)](https://tex.z-dn.net/?f=v_%7Bf%7D%20%3Dv_%7Bi%7D%20%2B%20%28a%2At%29)
where:
Vf = final velocity = 25 [m/s]
Vi = initial velocity = 0
a = acceleration [m/s^2]
t = time = 8 [s]
The initial speed is zero as the bus starts to koverse from rest. The positive sign of the equation means that the bus increases its speed.
25 = 0 + a*8
a = 3.125 [m/s^2]
Answer:
The biggest difference is that gravity is an attractive force while electromagnetism is both an attractive and repelling force. Gravity happens between two objects depending on their masses, while electromagnetism is dependent on the objects' electric charges and the distance between them.
Explanation:
Answer:
Speed of river is 0.45 m/s
Speed of boat is 2.65 m/s
Explanation:
= Speed of river
= Speed of canoe
![v_r+v_c=2.8\ m/s](https://tex.z-dn.net/?f=v_r%2Bv_c%3D2.8%5C%20m%2Fs)
![v_r-v_c=-1.9\ m/s](https://tex.z-dn.net/?f=v_r-v_c%3D-1.9%5C%20m%2Fs)
Adding the equations we get
![2v_r=0.9\\\Rightarrow v_r=\frac{0.9}{2}\\\Rightarrow v_r=0.45\ m/s](https://tex.z-dn.net/?f=2v_r%3D0.9%5C%5C%5CRightarrow%20v_r%3D%5Cfrac%7B0.9%7D%7B2%7D%5C%5C%5CRightarrow%20v_r%3D0.45%5C%20m%2Fs)
![0.42+v_c=2.8\ m/s\\\Rightarrow v_c=2.8-0.45\\\Rightarrow v_c=2.65\ m/s](https://tex.z-dn.net/?f=0.42%2Bv_c%3D2.8%5C%20m%2Fs%5C%5C%5CRightarrow%20v_c%3D2.8-0.45%5C%5C%5CRightarrow%20v_c%3D2.65%5C%20m%2Fs)
Speed of river is 0.45 m/s
Speed of boat is 2.65 m/s
Answer:
Explanation:
To stop a ball with high momentum in a small-time imparts a high amount of impact on hands. This is the reason for the stinging of hands.
The momentum of the ball is due to the mass and velocity. To prevent stinging in the hand one needs to lower his hands to increase the time of contact. In this way, the momentum transfer to the hands will be lesser.
Answer:
The acceleration is a = 2.75 [m/s^2]
Explanation:
In order to solve this problem we must use kinematics equations.
![v_{f} = v_{i} + a*t\\](https://tex.z-dn.net/?f=v_%7Bf%7D%20%3D%20v_%7Bi%7D%20%2B%20a%2At%5C%5C)
where:
Vf = final velocity = 13 [m/s]
Vi = initial velocity = 2 [m/s]
a = acceleration [m/s^2]
t = time = 4 [s]
Now replacing:
13 = 2 + (4*a)
(13 - 2) = 4*a
a = 2.75 [m/s^2]