Given Information:
Mass = m = 20000 kg
Height of ramp = h = 0.840 m
Length of ramp = L = 20 m
Required Information:
Uphill Force = F = ?
Answer:
F = 8232 N
Explanation:
The force can be found using the equation
F = mgsinθ
Where m is the mass of block, g is the acceleration due to gravity
Since the ramp can be modeled as an inclined plane so it can formed into a triangle, recall that in right angle triangle sinθ is equal to opposite over hypotenuse. The opposite is the height and hypotenuse is the ramp surface.
sinθ = h/L = 0.840/20 = 0.042
F = 20000*9.8*0.042
F = 8232 N
Therefore, an uphill force of 8232 N would be needed.
As you illustrate the problem, you may come up with the same diagram as the one shown in the attached picture. The relative velocity is the linear velocity between the two velocities. This is calculated by simply finding the difference of their velocities. Since, the velocity is with respect to Jane relative to Mary, the solution is as follows:
Relative velocity = Velocity of Jane - Velocity of Mary
Relative Velocity = 4.67 m/s - 3.59 m/s =
1.08 m/s
Answer:

Explanation:
Time period of the revolution of the disc is given as

now the angular speed of the disc is given as

so we will have


now at the rim position of the disc the net force on the penny is due to friction force
So we will have

here we will have




Answer : The correct option is, (D) A machine does 400 joules of work in 5 seconds.
Explanation :
Power : It is defined a the rate of doing work per unit time.
Formula used :

where,
P = power
w = work done
t = time
Now we have to determine the rate of power for the following options.
(A) A machine does 200 joules of work in 10 seconds.

(B) A machine does 400 joules of work in 10 seconds.

(C) A machine does 200 joules of work in 5 seconds.

(D) A machine does 400 joules of work in 5 seconds.

From this we conclude that, a machine does 400 joules of work in 5 seconds has the highest rate of power.
Hence, the correct option is, (D)