Physics Answers

A 6-kg block lies on an inclined plane that slopes at 30 degrees to the horizontal. Determine the external force applied on the block parallel to the slope that causes the block to accelerate at 2 m/s² down the slope. Assume that the coefficient of kinetic friction between the block and the plane is 0.2.

Consider the operator Å= }(İxjy + JyJ). (a) Calculate the expectation value of  and à with respect to the state | j, m).

(b) Use the result of (a) to find an expression for A in terms of: j4, j2, P, Ϊ, Ĵª.

A toy rocket (m =0.80 kg), initially at rest, is launched vertically upward such that over a time of 7.0 s the toy rocket travels a vertical displacement of 18 m. If the force of gravity on the toy rocket is 7.84 N, calculate the upward applied force of the engines. (Ignore air resistance)

A child on a toboggan is pulled across a frictionless surface using a rope which provides a tension force of 42 N [W]. Calculate the combined mass of the child and toboggan if they accelerate at 1.90 m/s2 [W] along the ground.

An arc with radius R=0.25m and length  l=π/12 meter carries 3A current. What is the magnetic field B at the center of the arc.

Question-3

In Fig. 3, 12 electrons (of charge e) are equally spaced and fixed around a circle of radius R. Relative to V=0 at infinity, what are the electric potential and electric field at the center C of the circle due to these electrons?

Fig-3 (a) twelve electrons uniformly spaced around a circle. (b)The electrons no uniformly spaced along an arc of the original circle.

Prove that the gravitational acceleration on the surface of the moon is 1/6 from the gravitational acceleration on the surface of the earth.(G=6.67x10^-11N m^-2 kg^-2,mass of the moon=7.34767309x10^22kg,radius of moon=1.74x10^6m)

whats oscillation

 a ladder is set to rest against a very slippery wall at an angle of 55 °. How large must the coefficient of friction between the ladder and the floor be in order for the ladder to remain upright?

8. A cannon flash is seen, but it takes 6s for the sound to reach the persons ear

How far away was the cannon?