Answer:
A book on its side exerts a greater force.
Explanation:
Pressure = Force / Area
Assuming that 1kg = 10N
2kg = 20N
Area of book lying flat = 0.3m × 0.2m
= 0.6m²
Pressure of book lying flat = 20N / 0.6m²
= 30Pa (1 s.f.)
Area of book on its side = 0.2m × 0.05m
= 0.01m²
Pressure of book on its side = 20N / 0.01m²
= 2000Pa (1 s.f.)
Since 2000Pa (1 s.f.) > 30Pa (1 s.f.), a book on its side applies greater pressure than lying flat.
Answer:
1000 N
Explanation:
First, we need to find the deceleration of the running back, which is given by:
![a=\frac{v-u}{t}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7Bv-u%7D%7Bt%7D)
where
v = 0 is his final velocity
u = 5 m/s is his initial velocity
t = 0.5 s is the time taken
Substituting, we have
![a=\frac{0-5 m/s}{0.5 s}=-10 m/s^2](https://tex.z-dn.net/?f=a%3D%5Cfrac%7B0-5%20m%2Fs%7D%7B0.5%20s%7D%3D-10%20m%2Fs%5E2)
And now we can calculate the force exerted on the running back, by using Newton's second law:
![F=ma=(100 kg)(-10 m/s^2)=-1000 N](https://tex.z-dn.net/?f=F%3Dma%3D%28100%20kg%29%28-10%20m%2Fs%5E2%29%3D-1000%20N)
so, the magnitude of the force is 1000 N.
Answer:
![s = 414.7 m\\](https://tex.z-dn.net/?f=s%20%3D%20414.7%20m%5C%5C)
Explanation:
The relationship between the linear distance covered by an object and its angular displacement is given by the following formula:
s = rθ
where,
s = distance traveled on road = ?
r radius of tires = diameter/2 = 2.2 m/2 = 1.1 m
θ = angular displacement = (60 rev)(2π rad/1 rev) = 377 rad
Therefore,
![s = (1.1 m)(377 rad)\\s = 414.7 m](https://tex.z-dn.net/?f=s%20%3D%20%281.1%20m%29%28377%20rad%29%5C%5Cs%20%3D%20414.7%20m)
The answer is C. Potential energy is when an object is at rest.
Kinetic is when an object is in motion.
![{\underline{\pink{\textsf{\textbf{ Answer : }}}}}](https://tex.z-dn.net/?f=%7B%5Cunderline%7B%5Cpink%7B%5Ctextsf%7B%5Ctextbf%7B%20Answer%20%3A%20%7D%7D%7D%7D%7D)
➡ 150hrs.
![{\underline{\pink{\textsf{\textbf{Explanation : }}}}}](https://tex.z-dn.net/?f=%7B%5Cunderline%7B%5Cpink%7B%5Ctextsf%7B%5Ctextbf%7BExplanation%20%3A%20%7D%7D%7D%7D%7D)
➡ Time = distance × speed
➡ Time = 15*10
➡ Time = 150hrs ans.