Answer:
the friction force in the reverse direction is 200 *0.4=80 N.
the net forward force acting on the box is therefore
Fnet= 100 - 80 N
= 20 N
acceleration = Fnet / mass
=Fnet *g/(weight)
=20 *9.8/200 = 0.98 m/s^2
Explanation:
Answer:
Approximate escape speed = 45.3 km/s
Explanation:
Escape speed

Here we have
Gravitational constant = G = 6.67 × 10⁻¹¹ m³ kg⁻¹ s⁻²
R = 1 AU = 1.496 × 10¹¹ m
M = 2.3 × 10³⁰ kg
Substituting

Approximate escape speed = 45.3 km/s
A closed system is a system that is completely isolated from its environment. The physical universe, as we currently understand it, appears to be a closed system. An open system is a system that has flows of information, energy, and/or matter between the system and its environment, and which adapts to the exchange.
D makes the most sense, but you just have to put two and two together and go with your gut feeling, first cross out the answers that don't make sense (A didnt make sense) and go from there! I hope the little bit above me helped you answer or decide :) Good luck!
Explanation:
Young' modulus is the ratio of normal stress to the longitudinal strain. Mathematically, it is given by :
Normal stress is given by force per unit area. Longitudinal strain is the change in length per unit original length.
The mathematical definition of Young's modulus is given by :
..........(1)
Where
is the change in length
F is the force
A is the area of cross section
So, the Young's modulus refers to the change in length of the object. Hence, the correct option is (b) "length".
I<span>n </span>direct current<span> (</span>DC), the electric charge (current<span>) only flows in one direction. Electric charge in </span>alternating current<span> (</span>AC<span>), on the other hand, changes direction periodically. The voltage in </span>AC<span> circuits also periodically reverses because the </span>current<span> changes direction.</span>