Answer:
Explanation:
mass, m = 1 kg
Position (2, 3 ) m
height, h = 2 m
acceleration due to gravity, g = 9.8 m/s^2
Here, no force is acting in horizontal direction, the force of gravity is acting in vertical direction, so the work done by the gravitational force is to be calculated.
Force mass x acceleration due to gravity
F = 1 x 9.8 = 9.8 N
Work = force x displacement x CosФ
Where, Ф be the angle between force vector and the displacement vector.
Here the value of Ф is 180° as the force acting vertically downward and the displacement is upward
So, W = 9.8 x 2 x Cos 180°
W = - 19.6 J
Thus, option (A) is correct.
Answer:
if you stretch a spring with k = 2, with a force of 4N, the extension will be 2m. the work done by us here is 4x2=8J. in other words, the energy transferred to the spring is 8J. but, the stored energy in the spring equals 1/2x2x2^2=4J (which is half of the work done by us in stretching it).
What models are you talking about
Answer: Option B) False
Explanation:
Current is the movement of negative charges called electrons. Protons, neutrons and electrons are the three subatomic particles that make up particles of the conductors that transmit current, however electrons are negatively charged and their gain or loss determines movement of electric current.
Thus, the statement is false
The velocity of shortening refers to the speed of the contraction from
the muscle shortening while lifting a load. The relationship between the
resistance and velocity of shortening is inverse. The greater the
resistance, the shorter the velocity of shortening and the smaller the
resistance, the larger the velocity of shortening.
Hopefully this help :)
