Answer:
The normal force the ground exerts on the block, F = -300 N
Explanation:
Given data,
The block pulled up with a tension force, T = 100 N
The weight of the block, W = 300 N
The weight of the block is due to the force of attraction of gravitation.
The surface exerts a force that is equal and opposite to the force acting on the block due to gravitation.
The weight of the block,
W = mg
300 N
The normal force the ground exerts on the block,
F = - mg
= - 300 N
Hence, the normal force the ground exerts on the block, F = -300 N
Answer:
At the end points of motion (either side) the velocity must be zero because the velocity is changing from - to + (it can't turn around around without passing thru zero,
The velocity will then increase to the midpoint of the motion.
m g h = 1/2 m v^2 where h is the vertical distance thru which the pendulum travels
Answer:
Explanation:
Initial moment of inertia of the earth I₁ = 2/5 MR² , M is mss of the earth and R is the radius . If ice melts , it forms an equivalent shell of mass 2.3 x 10¹⁹ Kg
Final moment of inertia I₂ = 2/5 M R² + 2/3 x 2.3 x 10¹⁹ x R²
For change in period of rotation we shall apply conservation of angular momentum law
I₁ ω₁ = I₂ ω₂ , ω₁ and ω₂ are angular velocities initially and finally .
I₁ / I₂ = ω₂ / ω₁
I₁ / I₂ = T₁ / T₂ , T₁ , T₂ are time period initially and finally .
T₂ / T₁ = I₂ / I₁
(2/5 M R² + 2/3 x 2.3 x 10¹⁹ x R²) / 2/5 MR²
1 + 5 / 3 x 2.3 x 10¹⁹ / M
= 1 + 5 / 3 x 2.3 x 10¹⁹ / 5.97 x 10²⁴
= 1 + .0000064
T₂ = 24 (1 + .0000064)
= 24 hours + .55 s
change in length of the day = .55 s .
The force that pushes charges through a wire is called voltage. Electric
current is the movement of the electrons caused by potential difference. For example,
in a circuit, the electrons in the bulb will not move without the potential
difference or voltage. When there is voltage, electric current occurs because
there is a driving force for the electrons in the wire to move.
Answer:
135,000 m
Explanation:
(1500 m/s) (90 s) = 135,000 m
