Answer:
Question 1)
a) The speed of the drums is increased from 2 ft/s to 4 ft/s in 4 s. From the below kinematic equations the acceleration of the drums can be determined.

This is the linear acceleration of the drums. Since the tape does not slip on the drums, by the rule of rolling without slipping,

where α is the angular acceleration.
In order to continue this question, the radius of the drums should be given.
Let us denote the radius of the drums as R, the angular acceleration of drum B is
α = 0.5/R.
b) The distance travelled by the drums can be found by the following kinematics formula:

One revolution is equal to the circumference of the drum. So, total number of revolutions is

Question 2)
a) In a rocket propulsion question, the acceleration of the rocket can be found by the following formula:

b) 
A. it is <span>located at a distance of 2.6 million light years from earth</span>
If friction is acting along the plane upwards
then in this case we will have
For equilibrium of 100 kg box on inclined plane we have

also for other side of hanging mass we have

now we have




In other case we can assume that friction will act along the plane downwards
so now in that case we will have

also we have

now we have





<em>So the range of angle will be 23.45 degree to 37 degree</em>
Answer:
8.4 kW
Explanation:
Using the Stefan-Boltzmann law,
P = εAσT4
Where:
P: Radiation Energy
ε: Emissivity of the Surface. Check emissivity table below of common materials.
A: Surface Area, in m^2.
σ: Stefan-Boltzmann Constant, σ=5.67 × 10-8 W/m2•K4
T: Temperature
Plugging in values,
P = 0.85 x 3.328 x 5.67 x 10^(-8) x 205
P = 8383 W or 8.4 kW
Given :
A 13.3 kg box sliding across the ground decelerates at 2.42 m/s².
To Find :
The coefficient of kinetic friction.
Solution :
Frictional force applied to the box is :
....1)
Also, force of friction is given by :
....2)
Equating equation 1) and 2), we get :

Therefore, the coefficient of kinetic friction is 0.247 .