Answer: 29.50 m
Explanation: In order to calculate the higher accelation to stop a train without moving the crates inside the wagon which is traveling at constat speed we have to use the second Newton law so that:
f=μ*N the friction force is equal to coefficient of static friction multiply the normal force (m*g).
f=m.a=μ*N= m*a= μ*m*g= m*a
then
a=μ*g=0.32*9.8m/s^2= 3.14 m/s^2
With this value we can determine the short distance to stop the train
as follows:
x= vo*t- (a/2)* t^2
Vf=0= vo-a*t then t=vo/a
Finally; x=vo*vo/a-a/2*(vo/a)^2=vo^2/2a= (49*1000/3600)^2/(2*3.14)=29.50 m
F=ma
Tension - weight = mass x acceleration
T - 5(9.81) = 5 x 1
T = 5 + 5(9.81)
T = 54.05 N
T ≈ 54 N
Answer: C
Explanation:
Find the acceleration using this kinematic equation:
Now use this kinematic equation to find the displacement:
The answer should be D but if its not then im sorrry, idk
Answer:
1960 J
Explanation:
Potential energy is given as the product of mass, height and acceleration due to gravity and expressed as mgh where m represent the mass of the swimmer, g is acceleration due to gravity and h is the height. Since the swimmer has just gone 4 m from the surface, that is the height that potential energy is converted to kinetic energy. This follows the law of transformation of energy since the energy can't be lost but rather transformed from one state to another. Therefore, substituting 50 kg for m, 4 m for h and 9.8 for g we obtain that PE=50*4*9.8=1960 J. Since it's not among the options here, maybe it is option D
