Answer:
Explanation:
We shall apply concept of impulse
Impulse = Force x time
= Force x 2 x 10⁻³ N.s
impulse = change in momentum
change in momentum
= .4 x 4 - ( - .4 x 2 )
= 2.4
Force x 2 x 10⁻³ = 2.4
Force = 2.4 / 2 x 10⁻³
= 1.2 x 10³ N .
average magnitude of the force exerted by floor = 1.2 x 10³ N
If R be reaction force by earth
R - mg = 1.2 x 10³
R = 1.2 x 10³ + mg
= 1200 + .4 x 9.8
= 1200 +3.92
= 1203 .92 N .
Answer:

Explanation:
Given that,
The radius of a flywheel, r = 0.3 m
Angular acceleration of a flywheel, 
We need to find the magnitude of the tangential acceleration after 2.00 s of acceleration.
The relation between the tangential and angular acceleration is given by :

So, the required magnitude of tangential acceleration is
.
Answer:
13.4cm
Explanation:
According to Rayleigh’s criterion the angular resolution to distinguish two objects is given by:

θ = 50.0*10^-7 rad
λ: wavelength of the light = 550nm
b = diameter of the objective
By doing b the subject of the formula and replacing the values of the angle and wavelength you obtain:

hence, the smallest diameter objective lens is 13.4cm
Answer:
D) 735 J(oules)
Explanation:
Work is defined as force * distance
Force is defined as mass * acceleration
Given a mass of 15 kg and a gravitational acceleration of 9.8 m/s² since the box is being lifted up, the force being applied to the box is 15 kg * 9.8 m/s² = 147 N
Since the distance is 5 meters, the work done is 147 N * 5 m = 735 N/m = 735 J, making D the correct answer.
Answer:
gfhvgtrtjrgvfjrrgfrfftuyrisnhdvfcgfridkjhsybvvtfvjfcgvwjfccegvghcvgrcgvrekgvrkgvkvvrvkvfgkerruuyti