Answer:
0.68 s
Explanation:
We are given that
Initial velocity of box=![u=13m/s](https://tex.z-dn.net/?f=u%3D13m%2Fs)
Final velocity of box=v=11.5 m/s
Distance=d=8.5 m
We have to find the time taken by box to slow by this amount.
We know that
![v^2-u^2=2as](https://tex.z-dn.net/?f=v%5E2-u%5E2%3D2as)
Substitute the values
![(11.5)^2-(13)^2=2a(8.5)](https://tex.z-dn.net/?f=%2811.5%29%5E2-%2813%29%5E2%3D2a%288.5%29)
![132.25-169=17a](https://tex.z-dn.net/?f=132.25-169%3D17a)
![-36.75=17a](https://tex.z-dn.net/?f=-36.75%3D17a)
![a=\frac{-36.75}{17}=-2.2m/s^2](https://tex.z-dn.net/?f=a%3D%5Cfrac%7B-36.75%7D%7B17%7D%3D-2.2m%2Fs%5E2)
We know that
Acceleration=![a=\frac{v-u}{t}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7Bv-u%7D%7Bt%7D)
Substitute the values
![-2.2=\frac{11.5-13}{t}](https://tex.z-dn.net/?f=-2.2%3D%5Cfrac%7B11.5-13%7D%7Bt%7D)
![-2.2=\frac{-1.5}{t}](https://tex.z-dn.net/?f=-2.2%3D%5Cfrac%7B-1.5%7D%7Bt%7D)
![t=\frac{1.5}{2.2}=0.68 s](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B1.5%7D%7B2.2%7D%3D0.68%20s)
Hence, the time taken by box to slow by this amount=0.68 s
Answer:
F = 120 N
Explanation:
Given that,
The mass of a runner, m = 60 kg
Acceleration of the runner, a = 2 m/s²
We need to find the force provided from her legs. The formula for force is given by :
F = ma
Substitute all the values,
F = 60 kg × 2 m/s²
= 120 N
So, the required force is equal to 120 N.
Answer:
P.E = 1764 Joules
Explanation:
Given the following data;
Mass = 6kg
Height = 30m
We know that acceleration due to gravity is equal to 9.8m/s²
To find the potential energy;
Potential energy can be defined as an energy possessed by an object or body due to its position.
Mathematically, potential energy is given by the formula;
![P.E = mgh](https://tex.z-dn.net/?f=%20P.E%20%3D%20mgh)
Where,
P.E represents potential energy measured in Joules.
m represents the mass of an object.
g represents acceleration due to gravity measured in meters per seconds square.
h represents the height measured in meters.
Substituting into the equation, we have;
P.E = 6 * 9.8 * 30
P.E = 1764 Joules
Answer:
The kinetic theory of matter can be used to explain how solids, liquids and gases are interchangeable as a result of increase or decrease in heat energy. When an object is heated the motion of the particles increases as the particles become more energetic